Subcutaneous Electrode with Improved Contact Shape for Transthoracic Conduction

ABSTRACT

One embodiment of the present invention provides a lead electrode assembly for use with an implantable cardioverter-defibrillator subcutaneously implanted outside the ribcage between the third and twelfth ribs comprising the electrode.

RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.11/429,089, filed May 5, 2006 and now U.S. Pat. No. 7,657,322; which isa continuation of U.S. patent application Ser. No. 10/013,980, filedNov. 5, 2001 and now U.S. Pat. No. 7,065,410; which is acontinuation-in-part of U.S. patent application Ser. No. 09/663,607,filed Sep. 18, 2000 and now U.S. Pat. No. 6,721,597; and acontinuation-in-part of U.S. patent application Ser. No. 09/663,606,filed Sep. 18, 2000 and now U.S. Pat. No. 6,647,292; and acontinuation-in-part of U.S. patent application Ser. No. 09/941,814,filed Aug. 27, 2001, abandoned, the entire disclosures of which are allhereby incorporated by reference.

FIELD

The present invention relates to an apparatus and method for performingelectrical cardioversion/defibrillation and optional pacing of the heartvia a totally subcutaneous non-transvenous system.

BACKGROUND

Defibrillation/cardioversion is a technique employed to counterarrhythmic heart conditions including some tachycardias in the atriaand/or ventricles. Typically, electrodes are employed to stimulate theheart with electrical impulses or shocks, of a magnitude substantiallygreater than pulses used in cardiac pacing. Shocks used fordefibrillation therapy can comprise a biphasic truncated exponentialwaveform. As for pacing, a constant current density is desired to reduceor eliminate variability due to the electrode/tissue interface.

Defibrillation/cardioversion systems include body implantable electrodesthat are connected to a hermetically sealed container housing theelectronics, battery supply and capacitors. The entire system isreferred to as implantable cardioverter/defibrillators (ICDs). Theelectrodes used in ICDs can be in the form of patches applied directlyto epicardial tissue, or, more commonly, are on the distal regions ofsmall cylindrical insulated catheters that typically enter thesubclavian venous system, pass through the superior vena cava, and intoone or more endocardial areas of the heart. Such electrode systems arecalled intravascular or transvenous electrodes. U.S. Pat. Nos.4,603,705; 4,693,253; 4,944,300; and 5,105,810, the disclosures of whichare all incorporated herein by reference, disclose intravascular ortransvenous electrodes, employed either alone, in combination with otherintravascular or transvenous electrodes, or in combination with anepicardial patch or subcutaneous electrodes. Compliant epicardialdefibrillator electrodes are disclosed in U.S. Pat. Nos. 4,567,900 and5,618,287, the disclosures of which are incorporated herein byreference. A sensing epicardial electrode configuration is disclosed inU.S. Pat. No. 5,476,503, the disclosure of which is incorporated hereinby reference.

In addition to epicardial and transvenous electrodes, subcutaneouselectrode systems have also been developed. For example, U.S. Pat. Nos.5,342,407 and 5,603,732, the disclosures of which are incorporatedherein by reference, teach the use of a pulse monitor/generatorsurgically implanted into the abdomen and subcutaneous electrodesimplanted in the thorax. This system is far more complicated to use thancurrent ICD systems using transvenous lead systems together with anactive can electrode and therefore it has no practical use. It has infact never been used because of the surgical difficulty of applying sucha device (3 incisions), the impractical abdominal location of thegenerator and the electrically poor sensing and defibrillation aspectsof such a system.

Recent efforts to improve the efficiency of ICDs have led manufacturersto produce ICDs which are small enough to be implanted in the pectoralregion. In addition, advances in circuit design have enabled the housingof the ICD to form a subcutaneous electrode. Some examples of ICDs inwhich the housing of the ICD serves as an optional additional electrodeare described in U.S. Pat. Nos. 5,133,353; 5,261,400; 5,620,477; and5,658,321, the disclosures of which are incorporated herein byreference.

ICDs are now an established therapy for the management of lifethreatening cardiac rhythm disorders, primarily ventricular fibrillation(V-Fib). ICDs are very effective at treating V-Fib, but are therapiesthat still require significant surgery.

As ICD therapy becomes more prophylactic in nature and used inprogressively less ill individuals, especially children at risk ofcardiac arrest, the requirement of ICD therapy to use intravenouscatheters and transvenous leads is an impediment to very long termmanagement as most individuals will begin to develop complicationsrelated to lead system malfunction sometime in the 5-10 year time frame,often earlier. In addition, chronic transvenous lead systems, theirreimplantation and removals, can damage major cardiovascular venoussystems and the tricuspid valve, as well as result in life threateningperforations of the great vessels and heart. Consequently, use oftransvenous lead systems, despite their many advantages, are not withouttheir chronic patient management limitations in those with lifeexpectancies of >5 years. The problem of lead complications is evengreater in children where body growth can substantially altertransvenous lead function and lead to additional cardiovascular problemsand revisions. Moreover, transvenous ICD systems also increase cost andrequire specialized interventional rooms and equipment as well asspecial skill for insertion. These systems are typically implanted bycardiac electrophysiologists who have had a great deal of extratraining.

In addition to the background related to ICD therapy, the presentinvention requires a brief understanding of a related therapy, theautomatic external defibrillator (AED). AEDs employ the use of cutaneouspatch electrodes, rather than implantable lead systems, to effectdefibrillation under the direction of a bystander user who treats thepatient suffering from V-Fib with a portable device containing thenecessary electronics and power supply that allows defibrillation. AEDscan be nearly as effective as an ICD for defibrillation if applied tothe victim of ventricular fibrillation promptly, i.e., within 2 to 3minutes of the onset of the ventricular fibrillation.

AED therapy has great appeal as a tool for diminishing the risk of deathin public venues such as in air flight. However, an AED must be used byanother individual, not the person suffering from the potential fatalrhythm. It is more of a public health tool than a patient-specific toollike an ICD. Because >75% of cardiac arrests occur in the home, and overhalf occur in the bedroom, patients at risk of cardiac arrest are oftenalone or asleep and cannot be helped in time with an AED. Moreover, itssuccess depends to a reasonable degree on an acceptable level of skilland calm by the bystander user.

What is needed therefore, especially for children and for prophylacticlong term use for those at risk of cardiac arrest, is a combination ofthe two forms of therapy which would provide prompt and near-certaindefibrillation, like an ICD, but without the long-term adverse sequelaeof a transvenous lead system while simultaneously using most of thesimpler and lower cost technology of an AED. What is also needed is acardioverter/defibrillator that is of simple design and can becomfortably implanted in a patient for many years.

SUMMARY

One embodiment of the present invention provides a lead electrodeassembly for use with an implantable cardioverter-defibrillatorsubcutaneously implanted outside the ribcage between the third andtwelfth ribs comprising an electrode.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the invention, reference is now made tothe drawings where like numerals represent similar objects throughoutthe figures where:

FIG. 1 is a schematic view of a Subcutaneous ICD (S-ICD) of the presentinvention;

FIG. 2 is a schematic view of an alternate embodiment of a subcutaneouselectrode of the present invention;

FIG. 3 is a schematic view of an alternate embodiment of a subcutaneouselectrode of the present invention;

FIG. 4 is a schematic view of the S-ICD and lead of FIG. 1subcutaneously implanted in the thorax of a patient;

FIG. 5 is a schematic view of the S-ICD and lead of FIG. 2subcutaneously implanted in an alternate location within the thorax of apatient;

FIG. 6 is a schematic view of the S-ICD and lead of FIG. 3subcutaneously implanted in the thorax of a patient;

FIG. 7 is a schematic view of the method of making a subcutaneous pathfrom the preferred incision and housing implantation point to atermination point for locating a subcutaneous electrode of the presentinvention;

FIG. 8 is a schematic view of an introducer set for performing themethod of lead insertion of any of the described embodiments;

FIG. 9 is a schematic view of an alternative S-ICD of the presentinvention illustrating a lead subcutaneously and serpiginously implantedin the thorax of a patient for use particularly in children;

FIG. 10 is a schematic view of an alternate embodiment of an S-ICD ofthe present invention;

FIG. 11 is a schematic view of the S-ICD of FIG. 10 subcutaneouslyimplanted in the thorax of a patient;

FIG. 12 is a schematic view of yet a further embodiment where thecanister of the S-ICD of the present invention is shaped to beparticularly useful in placing subcutaneously adjacent and parallel to arib of a patient;

FIG. 13 is a schematic of a different embodiment where the canister ofthe S-ICD of the present invention is shaped to be particularly usefulin placing subcutaneously adjacent and parallel to a rib of a patient;

FIG. 14 is a schematic view of a Unitary Subcutaneous ICD (US-ICD) ofthe present invention;

FIG. 15 is a schematic view of the US-ICD subcutaneously implanted inthe thorax of a patient;

FIG. 16 is a schematic view of the method of making a subcutaneous pathfrom the preferred incision for implanting the US-ICD;

FIG. 17 is a schematic view of an introducer for performing the methodof US-ICD implantation;

FIG. 18 is an exploded schematic view of an alternate embodiment of thepresent invention with a plug-in portion that contains operationalcircuitry and means for generating cardioversion/defibrillation shockwaves;

FIG. 19( a) is a side plan view of an embodiment of a lead electrodeassembly with a top-mounted fin;

FIG. 19( b) is a top plan view of an embodiment of a lead electrodeassembly with a top-mounted fin;

FIG. 19( c) is a side plan view of a section of the lead in anembodiment of the lead electrode assembly;

FIG. 19( d) is a cross-sectional view of a filar in the lead in anembodiment of the lead electrode assembly;

FIG. 19( e) is a cross-sectional view of the lead fastener of anembodiment of a lead electrode assembly;

FIG. 19( f) is an exploded view of the lead fastener of an embodiment ofa lead electrode assembly;

FIG. 20( a) is a cross-sectional front plan view of an embodiment of alead electrode assembly with a top-mounted fin;

FIG. 20( b) is a top plan view of an embodiment of a lead electrodeassembly with a top-mounted fin;

FIG. 21( a) is a perspective view of an embodiment of a lead electrodeassembly with a top-mounted fin;

FIG. 22( a) is a cross-sectional side plan view of an embodiment of alead electrode assembly with a top-mounted fin and a molded cover;

FIG. 22( b) is a cross-sectional side plan view of an embodiment of alead electrode assembly with a top-mounted fin that is slope-shaped anda molded cover;

FIG. 22( c) is cross-sectional front plan view of an embodiment of alead electrode assembly with a top-mounted fin and a molded cover;

FIG. 22( d) is an exploded top plan view of the lead fastener in anembodiment of a lead electrode assembly with a top-mounted fin and amolded cover;

FIG. 22( e) is a bottom plan view of an embodiment of a lead electrodeassembly with a top-mounted fin and a molded cover;

FIG. 22( f) is a side plan view of an embodiment of a lead electrodeassembly with a top-mounted fin and a molded cover;

FIG. 22( g) is a top plan view of an embodiment of a lead electrodeassembly with a top-mounted fin and a molded cover;

FIG. 23( a) is a side plan view of an embodiment of a lead electrodeassembly with an elongated top-mounted fin and a molded cover;

FIG. 23( b) is a top plan view of an embodiment of a lead electrodeassembly with an elongated top-mounted fin and a molded cover;

FIG. 23( c) is a bottom plan view of an embodiment of a lead electrodeassembly with an elongated top-mounted fin and a molded cover;

FIG. 24 is a side plan view of a lead electrode assembly demonstratingthe curvature of the electrode;

FIG. 25( a) is a top plan view of the backing layer and electrode of anembodiment of a lead electrode assembly with a side-mounted fin;

FIG. 25( b) is a side plan view of the backing layer and electrode of anembodiment of a lead electrode assembly with a side-mounted fin;

FIG. 25( c) is a bottom plan view of an embodiment of a lead electrodeassembly with a side-mounted fin;

FIG. 25( d) is a bottom plan view of an embodiment of a lead electrodeassembly with a side-mounted fin with a sloped shape;

FIG. 26( a) is a side plan view of a lead electrode assembly with atop-mounted loop;

FIG. 26( b) is a cross-sectional rear plan view of a lead electrodeassembly with a top-mounted loop;

FIG. 26( c) is a top plan view of a lead electrode assembly with atop-mounted loop;

FIG. 27( a) is a top plan view of a backing layer for use in anembodiment of a lead electrode assembly with a top-mounted fin formed aspart of the backing layer;

FIG. 27( b) is a top plan view of an embodiment of a lead electrodeassembly with a top-mounted fin formed as part of the backing layer;

FIG. 27( c) is a side plan view of an embodiment of a lead electrodeassembly with a top-mounted fin formed as part of the backing layer;

FIG. 27( d) is a front plan view of an embodiment of a lead electrodeassembly with a top-mounted fin formed as part of a backing layer;

FIG. 27( e) is a side plan view of an embodiment of a lead electrodeassembly with a top-mounted fin formed as part of a two-piece backinglayer;

FIG. 27( f) is a front plan view of an embodiment of a lead electrodeassembly with a top-mounted fin formed as part of a two-piece backinglayer;

FIG. 28( a) is a front plan view of the embodiment of the lead electrodeassembly of FIGS. 27( e) and (f) in an upright position;

FIG. 28( b) is a front plan view of the embodiment of the lead electrodeassembly of FIGS. 27( e) and (f) illustrating the ability of the fin tofold;

FIG. 29( a) is a front plan view of an embodiment of a lead electrodeassembly with a top-mounted tube formed as part of a backing layer;

FIG. 29( b) is a side plan view of an embodiment of a lead electrodeassembly with a top-mounted tube formed as part of a backing layer;

FIG. 29( c) is a top plan view of an embodiment of a lead electrodeassembly with a top-mounted tube formed as part of a backing layer;

FIG. 30( a) is a front plan view of an embodiment of a lead electrodeassembly with a top-mounted fin connected with flexible joining materialin an upright position;

FIG. 30( b) is a front plan view of an embodiment of a lead electrodeassembly with a top-mounted fin connected with flexible joining materialin a folded position;

FIG. 30( c) is a top plan view of an embodiment of a lead electrodeassembly with a top-mounted fin connected with flexible joining materialin an upright position;

FIG. 31 is a perspective view of an embodiment of a lead electrodeassembly in which the appendage is a cylindrical tube;

FIG. 32 is a perspective view of an embodiment of a lead electrodeassembly in which the appendage is a tube with a substantiallytriangular cross section;

FIGS. 33( a)-(d) are top plan views of embodiments of lead electrodeassemblies illustrating shapes of the electrode and the lines of thelead;

FIGS. 33( e)-(h) are bottom plan views of embodiments of lead electrodeassemblies illustrating shapes of the electrode;

FIG. 34 is a perspective view of a custom hemostat for lead electrodeassembly implantation;

FIG. 35( a) is a perspective view of a patient's ribcage showing theorientation of the components in an implanted S-ICD system;

FIG. 35( b) is a cross-sectional side plan view of a patient's rib cage,skin, fat and the lead of the lead electrode assembly;

FIG. 36 is a front plan view illustrating the incision point for thesurgery to implant the lead electrode assembly;

FIG. 37( a) is a cross-sectional bottom plan view of a patient alongline 37(a) of FIG. 36 illustrating the creation of a subcutaneous pathfor implantation of the lead electrode assembly of an 5-ICD system;

FIG. 37( b) is a perspective view of a lead electrode assembly capturedby a custom hemostat;

FIG. 37( c) is a cross-sectional bottom plan view of a patient alongline 37(a) of FIG. 36 illustrating the implantation of a lead electrodeassembly via the subcutaneous path;

FIG. 37( d) is a top view of a lead electrode assembly captured by acustom hemostat;

FIG. 38( a) is a perspective view of a rail of an embodiment of the leadelectrode assembly;

FIG. 38( b) is a cross-sectional front plan view of an embodiment of thelead electrode assembly where the appendage is a rail;

FIG. 38( c) is a top plan view of an embodiment of the lead electrodeassembly where the appendage is a rail;

FIG. 39 is a top view of an embodiment of the lead electrode assemblywhere the appendage is a rail;

FIG. 40( a) is a perspective view of a lead electrode assemblymanipulation tool with a rail fork;

FIG. 40( b) is a top plan view of a lead electrode assembly manipulationtool with a rail fork;

FIG. 40( c) is a side plan view of a lead electrode assemblymanipulation tool with a rail fork;

FIG. 40( d) is a top plan view of a lead electrode assembly having arail captured by a lead electrode assembly manipulation tool with a railfork;

FIG. 41( a) is a cross-sectional side plan view of a lead electrodeassembly with a pocket;

FIG. 41( b) is a top plan view of a lead electrode assembly with apocket;

FIG. 41( c) is a cross-sectional side plan view of a lead electrodeassembly with a pocket and a fin;

FIG. 42( a) is a bottom plan view of a lead electrode assembly with apocket;

FIG. 42( b) is a top plan view of a lead electrode assembly with apocket;

FIG. 43( a) is a top plan view of a lead electrode assembly manipulationtool with a paddle;

FIG. 43( b) is a side plan view of a lead electrode assemblymanipulation tool with a paddle;

FIG. 43( c) is a top plan view of a lead electrode assembly with apocket captured by a lead electrode assembly manipulation tool with apaddle;

FIG. 44( a) is a cross-sectional rear plan view of a lead electrodeassembly with a first channel guide and a second channel guide;

FIG. 44( b) is a top plan view of a lead electrode assembly with a firstchannel guide and a second channel guide;

FIG. 45( a) is a top plan view of a lead electrode assembly manipulationtool with a channel guide fork;

FIG. 45( b) is a top plan view of a lead electrode assembly with a firstchannel guide and a second channel guide captured by a lead electrodeassembly manipulation tool with a channel guide fork;

FIG. 46( a) is a perspective view of a subcutaneous implantablecardioverter-defibrillator kit; and

FIG. 46( b) is a perspective view of a hemostat illustrating the lengthmeasurement.

DETAILED DESCRIPTION

Turning now to FIG. 1, the S-ICD of the present invention isillustrated. The S-ICD consists of an electrically active canister 11and a subcutaneous electrode 13 attached to the canister. The canisterhas an electrically active surface 15 that is electrically insulatedfrom the electrode connector block 17 and the canister housing 16 viainsulating area 14. The canister can be similar to numerous electricallyactive canisters commercially available in that the canister willcontain a battery supply, capacitor and operational circuitry.Alternatively, the canister can be thin and elongated to conform to theintercostal space. The circuitry will be able to monitor cardiac rhythmsfor tachycardia and fibrillation, and if detected, will initiatecharging the capacitor and then delivering cardioversion/defibrillationenergy through the active surface of the housing and to the subcutaneouselectrode. Examples of such circuitry are described in U.S. Pat. Nos.4,693,253 and 5,105,810, the entire disclosures of which are hereinincorporated by reference. The canister circuitry can providecardioversion/defibrillation energy in different types of waveforms. Inone embodiment, a 100 uF biphasic waveform is used of approximately10-20 ms total duration and with the initial phase containingapproximately ⅔ of the energy, however, any type of waveform can beutilized such as monophasic, biphasic, multiphasic or alternativewaveforms as is known in the art.

In addition to providing cardioversion/defibrillation energy, thecircuitry can also provide transthoracic cardiac pacing energy. Theoptional circuitry will be able to monitor the heart for bradycardiaand/or tachycardia rhythms. Once a bradycardia or tachycardia rhythm isdetected, the circuitry can then deliver appropriate pacing energy atappropriate intervals through the active surface and the subcutaneouselectrode. Pacing stimuli can be biphasic in one embodiment and similarin pulse amplitude to that used for conventional transthoracic pacing.

This same circuitry can also be used to deliver low amplitude shocks onthe T-wave for induction of ventricular fibrillation for testing S-ICDperformance in treating V-Fib as is described in U.S. Pat. No.5,129,392, the entire disclosure of which is hereby incorporated byreference. Also the circuitry can be provided with rapid induction ofventricular fibrillation or ventricular tachycardia using rapidventricular pacing. Another optional way for inducing ventricularfibrillation would be to provide a continuous low voltage, i.e., about 3volts, across the heart during the entire cardiac cycle.

Another optional aspect of the present invention is that the operationalcircuitry can detect the presence of atrial fibrillation as described inOlson, W. et al. “Onset And Stability For Ventricular TachyarrhythmiaDetection in an Implantable Pacer-Cardioverter-Defibrillator,” Computersin Cardiology (1986) pp. 167-170. Detection can be provided via R-RCycle length instability detection algorithms. Once atrial fibrillationhas been detected, the operational circuitry will then provide QRSsynchronized atrial defibrillation/cardioversion using the same shockenergy and waveshape characteristics used for ventriculardefibrillation/cardioversion.

The sensing circuitry will utilize the electronic signals generated fromthe heart and will primarily detect QRS waves. In one embodiment, thecircuitry will be programmed to detect only ventricular tachycardias orfibrillations. The detection circuitry will utilize in its most directform, a rate detection algorithm that triggers charging of the capacitoronce the ventricular rate exceeds some predetermined level for a fixedperiod of time: for example, if the ventricular rate exceeds 240 bpm onaverage for more than 4 seconds. Once the capacitor is charged, aconfirmatory rhythm check would ensure that the rate persists for atleast another 1 second before discharge. Similarly, terminationalgorithms could be instituted that ensure that a rhythm less than 240bpm persisting for at least 4 seconds before the capacitor charge isdrained to an internal resistor. Detection, confirmation and terminationalgorithms as are described above and in the art can be modulated toincrease sensitivity and specificity by examining QRS beat-to-beatuniformity, QRS signal frequency content, R-R interval stability data,and signal amplitude characteristics all or part of which can be used toincrease or decrease both sensitivity and specificity of S-ICDarrhythmia detection function.

In addition to use of the sense circuitry for detection of V-Fib orV-Tach by examining the QRS waves, the sense circuitry can check for thepresence or the absence of respiration. The respiration rate can bedetected by monitoring the impedance across the thorax usingsubthreshold currents delivered across the active can and the highvoltage subcutaneous lead electrode and monitoring the frequency inundulation in the waveform that results from the undulations oftransthoracic impedance during the respiratory cycle. If there is noundulation, then the patient is not respiring and this lack ofrespiration can be used to confirm the QRS findings of cardiac arrest.The same technique can be used to provide information about therespiratory rate or estimate cardiac output as described in U.S. Pat.Nos. 6,095,987; 5,423,326; and 4,450,527, the entire disclosures ofwhich are incorporated herein by reference.

The canister of the present invention can be made out of titanium alloyor other presently preferred electrically active canister designs.However, it is contemplated that a malleable canister that can conformto the curvature of the patient's chest will be preferred. In this waythe patient can have a comfortable canister that conforms to the shapeof the patient's rib cage. Examples of conforming canisters are providedin U.S. Pat. No. 5,645,586, the entire disclosure of which is hereinincorporated by reference. Therefore, the canister can be made out ofnumerous materials such as medical grade plastics, metals, and alloys.In the preferred embodiment, the canister is smaller than 60 cc volumehaving a weight of less than 100 gms for long term wearability,especially in children. The canister and the lead of the S-ICD can alsouse fractal or wrinkled surfaces to increase surface area to improvedefibrillation capability. Because of the primary prevention role of thetherapy and the likely need to reach energies over 40 Joules, a featureof one embodiment is that the charge time for the therapy isintentionally left relatively long to allow capacitor charging withinthe limitations of device size. Examples of small ICD housings aredisclosed in U.S. Pat. Nos. 5,597,956 and 5,405,363, the entiredisclosures of which are herein incorporated by reference.

Different subcutaneous electrodes 13 of the present invention areillustrated in FIGS. 1-3. Turning to FIG. 1, the lead 21 for thesubcutaneous electrode is preferably composed of silicone orpolyurethane insulation. The electrode is connected to the canister atits proximal end via connection port 19 which is located on anelectrically insulated area 17 of the canister. The electrodeillustrated is a composite electrode with three different electrodesattached to the lead. In the embodiment illustrated, an optional anchorsegment 52 is attached at the most distal end of the subcutaneouselectrode for anchoring the electrode into soft tissue such that theelectrode does not dislodge after implantation.

The most distal electrode on the composite subcutaneous electrode is acoil electrode 27 that is used for delivering the high voltagecardioversion/defibrillation energy across the heart. The coilcardioversion/defibrillation electrode is about 5-10 cm in length.Proximal to the coil electrode are two sense electrodes, a first senseelectrode 25 is located proximally to the coil electrode and a secondsense electrode 23 is located proximally to the first sense electrode.The sense electrodes are spaced far enough apart to be able to have goodQRS detection. This spacing can range from 1 to 10 cm with 4 cm beingpresently preferred. The electrodes may or may not be circumferentialwith the preferred embodiment. Having the electrodes non-circumferentialand positioned outward, toward the skin surface, is a means to minimizemuscle artifact and enhance QRS signal quality. The sensing electrodesare electrically isolated from the cardioversion/defibrillationelectrode via insulating areas 29. Similar types ofcardioversion/defibrillation electrodes are currently commerciallyavailable in a transvenous configuration. For example, U.S. Pat. No.5,534,022, the entire disclosure of which is herein incorporated byreference, discloses a composite electrode with a coilcardioversion/defibrillation electrode and sense electrodes.Modifications to this arrangement are contemplated within the scope ofthe invention. One such modification is illustrated in FIG. 2 where thetwo sensing electrodes 25 and 23 are non-circumferential sensingelectrodes and one is located at the distal end, the other is locatedproximal thereto with the coil electrode located in between the twosensing electrodes. In this embodiment, the sense electrodes are spacedabout 6 to about 12 cm apart depending on the length of the coilelectrode used. FIG. 3 illustrates yet a further embodiment where thetwo sensing electrodes are located at the distal end to the compositeelectrode with the coil electrode located proximally thereto. Otherpossibilities exist and are contemplated within the present invention,for example, having only one sensing electrode, either proximal ordistal to the coil cardioversion/defibrillation electrode with the coilserving as both a sensing electrode and a cardioversion/defibrillationelectrode.

It is also contemplated within the scope of the invention that thesensing of QRS waves (and transthoracic impedance) can be carried outvia sense electrodes on the canister housing or in combination with thecardioversion/defibrillation coil electrode and/or the subcutaneous leadsensing electrode(s). In this way, sensing could be performed via theone coil electrode located on the subcutaneous electrode and the activesurface on the canister housing. Another possibility would be to haveonly one sense electrode located on the subcutaneous electrode and thesensing would be performed by that one electrode and either the coilelectrode on the subcutaneous electrode or by the active surface of thecanister. The use of sensing electrodes on the canister would eliminatethe need for sensing electrodes on the subcutaneous electrode. It isalso contemplated that the subcutaneous electrode would be provided withat least one sense electrode, the canister with at least one senseelectrode, and if multiple sense electrodes are used on either thesubcutaneous electrode and/or the canister, that the best QRS wavedetection combination will be identified when the S-ICD is implanted andthis combination can be selected, activating the best sensingarrangement from all the existing sensing possibilities. Turning againto FIG. 2, two sensing electrodes 26 and 28 are located on theelectrically active surface 15 with electrical insulator rings 30 placedbetween the sense electrodes and the active surface. These canistersense electrodes could be switched off and electrically insulated duringand shortly after defibrillation/cardioversion shock delivery. Thecanister sense electrodes may also be placed on the electricallyinactive surface of the canister. In the embodiment of FIG. 2, there areactually four sensing electrodes, two on the subcutaneous lead and twoon the canister. In the preferred embodiment, the ability to changewhich electrodes are used for sensing would be a programmable feature ofthe S-ICD to adapt to changes in the patient physiology and size (in thecase of children) over time. The programming could be done via the useof physical switches on the canister, or as presently preferred, via theuse of a programming wand or via a wireless connection to program thecircuitry within the canister.

The canister could be employed as either a cathode or an anode of theS-ICD cardioversion/defibrillation system. If the canister is thecathode, then the subcutaneous coil electrode would be the anode.Likewise, if the canister is the anode, then the subcutaneous electrodewould be the cathode.

The active canister housing will provide energy and voltage intermediateto that available with ICDs and most AEDs. The typical maximum voltagenecessary for ICDs using most biphasic waveforms is approximately 750Volts with an associated maximum energy of approximately 40 Joules. Thetypical maximum voltage necessary for AEDs is approximately 2000-5000Volts with an associated maximum energy of approximately 200-360 Joulesdepending upon the model and waveform used. The S-ICD and the US-ICD ofthe present invention use maximum voltages in the range of about 50 toabout 3500 Volts and is associated with energies of about 0.5 to about350 Joules. The capacitance of the devices can range from about 25 toabout 200 micro farads.

The sense circuitry contained within the canister is highly sensitiveand specific for the presence or absence of life threatening ventriculararrhythmias. Features of the detection algorithm are programmable andthe algorithm is focused on the detection of V-FIB and high rate V-TACH(>240 bpm). Although the S-ICD of the present invention may rarely beused for an actual life threatening event, the simplicity of design andimplementation allows it to be employed in large populations of patientsat modest risk with modest cost by non-cardiac electrophysiologists.Consequently, the S-ICD of the present invention focuses mostly on thedetection and therapy of the most malignant rhythm disorders. As part ofthe detection algorithm's applicability to children, the upper raterange is programmable upward for use in children, known to have rapidsupraventricular tachycardias and more rapid ventricular fibrillation.Energy levels also are programmable downward in order to allow treatmentof neonates and infants.

Turning now to FIG. 4, the optimal subcutaneous placement of the S-ICDof the present invention is illustrated. As would be evidence to aperson skilled in the art, the actual location of the 5-ICD is in asubcutaneous space that is developed during the implantation process.The heart is not exposed during this process and the heart isschematically illustrated in the figures only for help in understandingwhere the canister and coil electrode are three dimensionally located inthe left mid-clavicular line approximately at the level of theinframammary crease at approximately the 5th rib. The lead 21 of thesubcutaneous electrode traverses in a subcutaneous path around thethorax terminating with its distal electrode end at the posterioraxillary line ideally just lateral to the left scapula. This way thecanister and subcutaneous cardioversion/defibrillation electrode providea reasonably good pathway for current delivery to the majority of theventricular myocardium.

FIG. 5 illustrates a different placement of the present invention. TheS-ICD canister with the active housing is located in the left posterioraxillary line approximately lateral to the tip of the inferior portionof the scapula. This location is especially useful in children. The lead21 of the subcutaneous electrode traverses in a subcutaneous path aroundthe thorax terminating with its distal electrode end at the anteriorprecordial region, ideally in the inframammary crease. FIG. 6illustrates the embodiment of FIG. 1 subcutaneously implanted in thethorax with the proximal sense electrodes 23 and 25 located atapproximately the left axillary line with thecardioversion/defibrillation electrode just lateral to the tip of theinferior portion of the scapula.

FIG. 7 schematically illustrates the method for implanting the S-ICD ofthe present invention. An incision 31 is made in the left anterioraxillary line approximately at the level of the cardiac apex. Thisincision location is distinct from that chosen for S-ICD placement andis selected specifically to allow both canister location more mediallyin the left inframammary crease and lead positioning more posteriorlyvia the introducer set (described below) around to the left posterioraxillary line lateral to the left scapula. That said, the incision canbe anywhere on the thorax deemed reasonably by the implanting physicianalthough in the preferred embodiment, the S-ICD of the present inventionwill be applied in this region. A subcutaneous pathway 33 is thencreated medially to the inframammary crease for the canister andposteriorly to the left posterior axillary line lateral to the leftscapula for the lead.

The S-ICD canister 11 is then placed subcutaneously at the location ofthe incision or medially at the subcutaneous region at the leftinframammary crease. The subcutaneous electrode 13 is placed with aspecially designed curved introducer set 40 (see FIG. 8). The introducerset comprises a curved trocar 42 and a stiff curved peel away sheath 44.The peel away sheath is curved to allow for placement around the ribcage of the patient in the subcutaneous space created by the trocar. Thesheath has to be stiff enough to allow for the placement of theelectrodes without the sheath collapsing or bending. Preferably thesheath is made out of a biocompatible plastic material and is perforatedalong its axial length to allow for it to split apart into two sections.The trocar has a proximal handle 41 and a curved shaft 43. The distalend 45 of the trocar is tapered to allow for dissection of asubcutaneous path 33 in the patient. Preferably, the trocar iscannulated having a central Lumen 46 and terminating in an opening 48 atthe distal end. Local anesthetic such as lidocaine can be delivered, ifnecessary, through the lumen or through a curved and elongated needledesigned to anesthetize the path to be used for trocar insertion shouldgeneral anesthesia not be employed. The curved peel away sheath 44 has aproximal pull tab 49 for breaking the sheath into two halves along itsaxial shaft 47. The sheath is placed over a guidewire inserted throughthe trocar after the subcutaneous path has been created. Thesubcutaneous pathway is then developed until it terminatessubcutaneously at a location that, if a straight line were drawn fromthe canister location to the path termination point the line wouldintersect a substantial portion of the left ventricular mass of thepatient. The guidewire is then removed leaving the peel away sheath. Thesubcutaneous lead system is then inserted through the sheath until it isin the proper location. Once the subcutaneous lead system is in theproper location, the sheath is split in half using the pull tab 49 andremoved. If more than one subcutaneous electrode is being used, a newcurved peel away sheath can be used for each subcutaneous electrode.

The S-ICD will have prophylactic use in adults where chronictransvenous/epicardial ICD lead systems pose excessive risk or havealready resulted in difficulty, such as sepsis or lead fractures. It isalso contemplated that a major use of the S-ICD system of the presentinvention will be for prophylactic use in children who are at risk forhaving fatal arrhythmias, where chronic transvenous lead systems posesignificant management problems. Additionally, with the use of standardtransvenous ICDs in children, problems develop during patient growth inthat the lead system does not accommodate the growth. FIG. 9 illustratesthe placement of the S-ICD subcutaneous lead system such that theproblem that growth presents to the lead system is overcome. The distalend of the subcutaneous electrode is placed in the same location asdescribed above providing a good location for the coilcardioversion/defibrillation electrode 27 and the sensing electrodes 23and 25. However, insulated lead 21 is no longer placed in a tautconfiguration. Instead, the lead is serpiginously placed with aspecially designed introducer trocar and sheath such that it hasnumerous waves or bends. As the child grows, the waves or bends willstraighten out lengthening the lead system while maintaining properelectrode placement. Although it is expected that fibrous scarringespecially around the defibrillation coil will help anchor it intoposition to maintain its posterior position during growth, a lead systemwith a distal tine or screw electrode anchoring system 52 can also beincorporated into the distal tip of the lead to facilitate leadstability (see FIG. 1). Other anchoring systems can also be used such ashooks, sutures, or the like.

FIGS. 10 and 11 illustrate another embodiment of the present S-ICDinvention. In this embodiment there are two subcutaneous electrodes 13and 13′ of opposite polarity to the canister. The additionalsubcutaneous electrode 13′ is essentially identical to the previouslydescribed electrode. In this embodiment the cardioversion/defibrillationenergy is delivered between the active surface of the canister and thetwo coil electrodes 27 and 27′. Additionally, provided in the canisteris means for selecting the optimum sensing arrangement between the foursense electrodes 23, 23′, 25, and 25′. The two electrodes aresubcutaneously placed on the same side of the heart. As illustrated inFIG. 6, one subcutaneous electrode 13 is placed inferiorly and the otherelectrode 13′ is placed superiorly. It is also contemplated with thisdual subcutaneous electrode system that the canister and onesubcutaneous electrode are the same polarity and the other subcutaneouselectrode is the opposite polarity.

Turning now to FIGS. 12 and 13, further embodiments are illustratedwhere the canister 11 of the S-ICD of the present invention is shaped tobe particularly useful in placing subcutaneously adjacent and parallelto a rib of a patient. The canister is long, thin, and curved to conformto the shape of the patient's rib. In the embodiment illustrated in FIG.12, the canister has a diameter ranging from about 0.5 cm to about 2 cmwithout 1 cm being presently preferred. Alternatively, instead of havinga circular cross sectional area, the canister could have a rectangularor square cross sectional area as illustrated in FIG. 13 without fallingoutside of the scope of the present invention. The length of thecanister can vary depending on the size of the patient's thorax. In anembodiment, the canister is about 5 cm to about 40 cm long with about 10being presently preferred. The canister is curved to conform to thecurvature of the ribs of the thorax. The radius of the curvature willvary depending on the size of the patient, with smaller radiuses forsmaller patients and larger radiuses for larger patients. The radius ofthe curvature can range from about 5 cm to about 35 cm depending on thesize of the patient. Additionally, the radius of the curvature need notbe uniform throughout the canister such that it can be shaped closer tothe shape of the ribs. The canister has an active surface 15 that islocated on the interior (concave) portion of the curvature and aninactive surface 16 that is located on the exterior (convex) portion ofthe curvature. The leads of these embodiments, which are not illustratedexcept for the attachment port 19 and the proximal end of the lead 21,can be any of the leads previously described above, with the leadillustrated in FIG. 1 being presently preferred.

The circuitry of this canister is similar to the circuitry describedabove. Additionally, the canister can optionally have at least one senseelectrode located on either the active surface of the inactive surfaceand the circuitry within the canister can be programmable as describedabove to allow for the selection of the best sense electrodes. It ispresently preferred that the canister have two sense electrodes 26 and28 located on the inactive surface of the canisters as illustrated,where the electrodes are spaced from about 1 to about 10 cm apart with aspacing of about 3 cm being presently preferred. However, the senseelectrodes can be located on the active surface as described above.

It is envisioned that the embodiment of FIG. 12 will be subcutaneouslyimplanted adjacent and parallel to the left anterior 5th rib, eitherbetween the 4th and 5th ribs or between the 5th and 6th ribs. Howeverother locations can be used.

Another component of the S-ICD of the present invention is a cutaneoustest electrode system designed to simulate the subcutaneous high voltageshock electrode system as well as the QRS cardiac rhythm detectionsystem. This test electrode system is comprised of a cutaneous patchelectrode of similar surface area and impedance to that of the S-ICDcanister itself together with a cutaneous strip electrode comprising adefibrillation strip as well as two button electrodes for sensing of theQRS. Several cutaneous strip electrodes are available to allow fortesting various bipole spacings to optimize signal detection comparableto the implantable system.

FIGS. 14, 15, 16, 17 and 18 depict particular US-ICD embodiments of thepresent invention. The various sensing, shocking and pacing circuitrydescribed in detail above with respect to the S-ICD embodiments mayadditionally be incorporated into the following US-ICD embodiments.Furthermore, particular aspects of any individual S-ICD embodimentdiscussed above may be incorporated, in whole or in part, into theUS-ICD embodiments depicted in the following figures.

Turning now to FIG. 14, the US-ICD of the present invention isillustrated. The US-ICD consists of a curved housing 1211 with a firstand second end. The first end 1413 is thicker than the second end 1215.This thicker area houses a battery supply, capacitor and operationalcircuitry for the US-ICD. The circuitry will be able to monitor cardiacrhythms for tachycardia and fibrillation, and if detected, will initiatecharging the capacitor and then delivering cardioversion/defibrillationenergy through the two cardioversion/defibrillating electrodes 1417 and1219 located on the outer surface of the two ends of the housing. Thecircuitry can provide cardioversion/defibrillation energy in differenttypes of waveforms. In one embodiment, a 100 uF biphasic waveform isused of approximately 10-20 ms total duration and with the initial phasecontaining approximately ⅔ of the energy, however, any type of waveformcan be utilized such as monophasic, biphasic, multiphasic or alternativewaveforms as is known in the art.

The housing of the present invention can be made out of titanium alloyor other presently preferred ICD designs. It is contemplated that thehousing is also made out of biocompatible plastic materials thatelectronically insulate the electrodes from each other. However, it iscontemplated that a malleable canister that can conform to the curvatureof the patient's chest will be preferred. In this way the patient canhave a comfortable canister that conforms to the unique shape of thepatient's rib cage. Examples of conforming ICD housings are provided inU.S. Pat. No. 5,645,586, the entire disclosure of which is hereinincorporated by reference. In the preferred embodiment, the housing iscurved in the shape of a 5th rib of a person. Because there are manydifferent sizes of people, the housing will come in differentincremental sizes to allow a good match between the size of the rib cageand the size of the US-ICD. The length of the US-ICD will range fromabout 15 to about 50 cm. Because of the primary preventative role of thetherapy and the need to reach energies over 40 Joules, a feature of thepreferred embodiment is that the charge time for the therapyintentionally be relatively long to allow capacitor charging within thelimitations of device size.

The thick end of the housing is currently needed to allow for theplacement of the battery supply, operational circuitry, and capacitors.It is contemplated that the thick end will be about 0.5 cm to about 2 cmwide with about 1 cm being presently preferred. As microtechnologyadvances, the thickness of the housing will become smaller.

The two cardioversion/defibrillation electrodes on the housing are usedfor delivering the high voltage cardioversion/defibrillation energyacross the heart. In the preferred embodiment, thecardioversion/defibrillation electrodes are coil electrodes, however,other cardioversion/defibrillation electrodes could be used such ashaving electrically isolated active surfaces or platinum alloyelectrodes. The coil cardioversion/defibrillation electrodes are about5-10 cm in length. Located on the housing between the twocardioversion/defibrillation electrodes are two sense electrodes 1425and 1427. The sense electrodes are spaced far enough apart to be able tohave good QRS detection. This spacing can range from 1 to 10 cm with 4cm being presently preferred. The electrodes may or may not becircumferential with the preferred embodiment. Having the electrodesnon-circumferential and positioned outward, toward the skin surface, isa means to minimize muscle artifact and enhance QRS signal quality. Thesensing electrodes are electrically isolated from thecardioversion/defibrillation electrode via insulating areas 1423.Analogous types of cardioversion/defibrillation electrodes are currentlycommercially available in a transvenous configuration. For example, U.S.Pat. No. 5,534,022, the entire disclosure of which is hereinincorporated by reference, discloses a composite electrode with a coilcardioversion/defibrillation electrode and sense electrodes.Modifications to this arrangement are contemplated within the scope ofthe invention. One such modification is to have the sense electrodes atthe two ends of the housing and have the cardioversion/defibrillationelectrodes located in between the sense electrodes. Another modificationis to have three or more sense electrodes spaced throughout the housingand allow for the selection of the two best sensing electrodes. If threeor more sensing electrodes are used, then the ability to change whichelectrodes are used for sensing would be a programmable feature of theUS-ICD to adapt to changes in the patient physiology and size over time.The programming could be done via the use of physical switches on thecanister, or as presently preferred, via the use of a programming wandor via a wireless connection to program the circuitry within thecanister.

Turning now to FIG. 15, the optimal subcutaneous placement of the US-ICDof the present invention is illustrated. As would be evident to a personskilled in the art, the actual location of the US-ICD is in asubcutaneous space that is developed during the implantation process.The heart is not exposed during this process and the heart isschematically illustrated in the figures only for help in understandingwhere the device and its various electrodes are three dimensionallylocated in the thorax of the patient. The US-ICD is located between theleft mid-clavicular line approximately at the level of the inframammarycrease at approximately the 5th rib and the posterior axillary line,ideally just lateral to the left scapula. This way the US-ICD provides areasonably good pathway for current delivery to the majority of theventricular myocardium.

FIG. 16 schematically illustrates the method for implanting the US-ICDof the present invention. An incision 1631 is made in the left anterioraxillary line approximately at the level of the cardiac apex. Asubcutaneous pathway is then created that extends posteriorly to allowplacement of the US-ICD. The incision can be anywhere on the thoraxdeemed reasonable by the implanting physician although in the preferredembodiment, the US-ICD of the present invention will be applied in thisregion. The subcutaneous pathway is created medially to the inframammarycrease and extends posteriorly to the left posterior axillary line. Thepathway is developed with a specially designed curved introducer 1742(see FIG. 17). The trocar has a proximal handle 1641 and a curved shaft1643. The distal end 1745 of the trocar is tapered to allow fordissection of a subcutaneous path in the patient. Preferably, the trocaris cannulated having a central lumen 1746 and terminating in an opening1748 at the distal end. Local anesthetic such as lidocaine can bedelivered, if necessary, through the lumen or through a curved andelongated needle designed to anesthetize the path to be used for trocarinsertion should general anesthesia not be employed. Once thesubcutaneous pathway is developed, the US-ICD is implanted in thesubcutaneous space, the skin incision is closed using standardtechniques.

As described previously, the US-ICDs of the present invention vary inlength and curvature. The US-ICDs are provided in incremental sizes forsubcutaneous implantation in different sized patients. Turning now toFIG. 18, a different embodiment is schematically illustrated in explodedview which provides different sized US-ICDs that are easier tomanufacture. The different sized US-ICDs will all have the same sizedand shaped thick end 1413. The thick end is hollow inside allowing forthe insertion of a core operational member 1853. The core membercomprises a housing 1857 which contains the battery supply, capacitorand operational circuitry for the US-ICD. The proximal end of the coremember has a plurality of electronic plug connectors. Plug connectors1861 and 1863 are electronically connected to the sense electrodes viapressure fit connectors (not illustrated) inside the thick end which arestandard in the art. Plug connectors 1865 and 1867 are alsoelectronically connected to the cardioverter/defibrillator electrodesvia pressure fit connectors inside the thick end. The distal end of thecore member comprises an end cap 1855, and a ribbed fitting 1859 whichcreates a water-tight seal when the core member is inserted into opening1851 of the thick end of the US-ICD.

The S-ICD and US-ICD, in alternative embodiments, have the ability todetect and treat atrial rhythm disorders, including atrial fibrillation.The S-ICD and US-ICD have two or more electrodes that provide afar-field view of cardiac electrical activity that includes the abilityto record the P-wave of the electrocardiogram as well as the QRS. Onecan detect the onset and offset of atrial fibrillation by referencing tothe P-wave recorded during normal sinus rhythm and monitoring for itschange in rate, morphology, amplitude and frequency content. Forexample, a well-defined P-wave that abruptly disappeared and wasreplaced by a low-amplitude, variable morphology signal would be astrong indication of the absence of sinus rhythm and the onset of atrialfibrillation. In an alternative embodiment of a detection algorithm, theventricular detection rate could be monitored for stability of the R-Rcoupling interval. In the examination of the R-R interval sequence,atrial fibrillation can be recognized by providing a near constantirregularly irregular coupling interval on a beat-by-beat basis. An R-Rinterval plot during AF appears “cloudlike” in appearance when severalhundred or thousands of R-R intervals are plotted over time whencompared to sinus rhythm or other supraventricular arrhythmias.Moreover, a distinguishing feature compared to other rhythms that areirregularly irregular, is that the QRS morphology is similar on abeat-by-beat basis despite the irregularity in the R-R couplinginterval. This is a distinguishing feature of atrial fibrillationcompared to ventricular fibrillation where the QRS morphology varies ona beat-by-beat basis. In yet another embodiment, atrial fibrillation maybe detected by seeking to compare the timing and amplitude relationshipof the detected P-wave of the electrocardiogram to the detected QRS(R-wave) of the electrocardiogram. Normal sinus rhythm has a fixedrelationship that can be placed into a template matching algorithm thatcan be used as a reference point should the relationship change.

In other aspects of the atrial fibrillation detection process, one mayinclude alternative electrodes that may be brought to bear in the S-ICDor US-ICD systems either by placing them in the detection algorithmcircuitry through a programming maneuver or by manually adding suchadditional electrode systems to the S-ICD or US-ICD at the time ofimplant or at the time of follow-up evaluation. One may also useelectrodes for the detection of atrial fibrillation that may or may notalso be used for the detection of ventricular arrhythmias given thedifferent anatomic locations of the atria and ventricles with respect tothe S-ICD or US-ICD housing and surgical implant sites.

Once atrial fibrillation is detected, the arrhythmia can be treated bydelivery of a synchronized shock using energy levels up to the maximumoutput of the device therapy for terminating atrial fibrillation or forother supraventricular arrhythmias. The S-ICD or US-ICD electrode systemcan be used to treat both atrial and ventricular arrhythmias not onlywith shock therapy but also with pacing therapy. In a further embodimentof the treatment of atrial fibrillation or other atrial arrhythmias, onemay be able to use different electrode systems than what is used totreat ventricular arrhythmias. Another embodiment would allow fordifferent types of therapies (amplitude, waveform, capacitance, etc.)for atrial arrhythmias compared to ventricular arrhythmias.

The core member of the different sized and shaped US-ICD will all be thesame size and shape. That way, during an implantation procedure,multiple sized US-ICDs can be available for implantation, each onewithout a core member. Once the implantation procedure is beingperformed, then the correct sized US-ICD can be selected and the coremember can be inserted into the US-ICD and then programmed as describedabove. Another advantage of this configuration is when the batterywithin the core member needs replacing it can be done without removingthe entire US-ICD.

FIG. 19( a) illustrates an embodiment of the subcutaneous lead electrodeor “lead electrode assembly” 100. The lead electrode assembly 100 isdesigned to provide an electrode 107 to be implanted subcutaneously inthe posterior thorax of a patient for delivery ofcardioversion/defibrillation energy. The lead electrode assembly 100 isfurther designed to provide a path for the cardioversion/defibrillationenergy to reach the electrode 107 from the operational circuitry withinthe canister 11 of an S-ICD such as the embodiment shown in FIG. 1.

The lead electrode assembly 100 comprises a connector 111, a lead 21, alead fastener 146, an electrode 107 and an appendage 118. The connector111 is connected to the lead 21. The lead 21 is further connected to theelectrode 107 with the lead fastener 146. The appendage 118 is mountedto the electrode 107.

The connector 111 provides an electrical connection between the lead 21and the operational circuitry within the canister 11 of an S-ICD such asthe embodiment shown in FIG. 1. Connector 111 is designed to mate withthe connection port 19 on the canister 11. In the embodiment underdiscussion, the connector 111 meets the IS-1 standard.

The lead 21 of the lead electrode assembly 100 provides an electricalconnection between the connector 111 and the electrode 107. The lead 21comprises a distal end 101 and a proximal end 102. The distal end 101 ofthe lead 21 is attached to the connector 111. The proximal end 102 ofthe lead 21 is attached to electrode 107 with the lead fastener 146.

The lead 21 has a lead length, I_(Lead), measured from the connector 111along the lead 21 to the lead fastener 146 of the electrode 107. Thelength of the lead 21 is approximately 25 cm. In alternativeembodiments, the lead lengths range between approximately 5 cm andapproximately 55 cm.

The lead fastener 146 provides a robust physical and electricalconnection between the lead 21 and the electrode 107. The lead fastener146 joins the proximal end 102 of the lead 21 to electrode 107.

The electrode 107 comprises an electrically conductive member designedto make contact with the tissue of the patient and transfercardioversion/defibrillation energy to the tissue of the patient fromthe S-ICD canister 11.

The electrode 107 illustrated is generally flat and planar, comprising atop surface 110, a bottom surface 115, a distal end 103 and a proximalend 104. The lead fastener 146 is attached to the top surface 110 of thedistal end 103 of the electrode 107.

The electrode 107 may have shapes other than planar. In an alternateembodiment, the electrode 107 is shaped like a coil.

The appendage 118 is a member attached to the electrode 107 that can begripped and used to precisely locate the lead electrode assembly 100during its surgical implantation within the patient.

The appendage 118 has a first end 105, a second end 106, a distal edge121 and a proximal edge 129. The second end 106 of the appendage 118 isattached to the top surface 110 of the electrode 107. The appendage 118is positioned such that its proximal edge 129 is within approximately 20mm of the proximal end 104 of the electrode 107. In alternateembodiments, the appendage 118 is attached to the electrode 107 in otherpositions.

It is useful at this point, to set out several general definitions forfuture reference in discussing the dimensions and placement ofappendages 118.

The appendage height, h_(Appendage), is defined as the distance from thepoint of the appendage 118 most distant from the electrode 107 to apoint of the appendage 118 closest to the electrode 107 measured along aline perpendicular to the top surface 110 of the electrode 107. Theappendage height of the appendage 118 illustrated, for example, would bemeasured between the first end 105 of the appendage 118 and the secondend 106 of the appendage 118.

The appendage height of the appendage 118 illustrated is approximately 5mm. In alternative embodiments, the appendage heights range betweenapproximately 1 mm and approximately 10 mm.

The appendage interface is defined as the part of the appendage 118 thatjoins it to the electrode 107. The appendage interface of the appendage118 illustrated, for example, would be the second end 106 of theappendage 118.

The appendage length, I_(Appendage), is the length of the appendage 118along the appendage interface. The appendage interface of the appendage118 illustrated, for example, would be the length of the second end 106of the appendage 118.

The appendage length of the appendage 118 illustrated in FIG. 19( a) isapproximately 1 cm. In alternative embodiments, appendage lengths rangebetween approximately 2 mm and approximately 6 cm. In an alternateembodiment, the appendage 118 is substantially as long as the electrode107.

More particularly, the appendage 118 of the embodiment illustrated is afin 120 comprising a fin core 122 (phantom view) and a coating 125.

The fin core 122 generally provides support for the fin 120. The fincore 122 has a first end 126 and a second end 127. The second end 127 ofthe fin core 122 is attached to the top surface 110 of the electrode107.

The fin core 122 comprises a metal selected from the group consistingessentially of titanium, nickel alloys, stainless steel alloys,platinum, platinum iridium, and mixtures thereof. In other embodiments,the fin core 122 comprises any rugged material that can be attached tothe first surface 110 of the electrode 107.

The coating 125 is disposed around the fin core 122. The coating 125provides a surface for the fin 120 that can be easily gripped during theimplantation of the lead electrode assembly 100. The coating 125covering the fin core 122 is composed of molded silicone. In analternative embodiment, the coating 125 may be any polymeric material.In this specification, the term polymeric material includes the group ofmaterials consisting of a polyurethane, a polyamide, apolyetheretherketone (PEEK), a polyether block amide (PEBA), apolytetrafluoroethylene (PTFE), a silicone and mixtures thereof.

In one embodiment, the fin 120 is reinforced with a layer of Dacron®polymer mesh attached to the inside of the coating 125. Dacron® is aregistered trademark of E.I. du Pont de Nemours and Company Corporation,Wilmington, Del. In another embodiment, the Dacron® polymer meshattached to the outside of the coating 125. In another embodiment, thefin 120 is reinforced with a layer of any polymeric material.

FIG. 19( b) illustrates a top view of the lead electrode assembly 100.The electrode 107 is substantially rectangular in shape, comprising afirst pair of sides 108, a second pair of sides 109 and four corners112. In an alternative embodiment the electrode 107 has a shape otherthan rectangular. In this embodiment, the corners 112 of the electrode107 are rounded. In an alternative embodiment the corners 112 of theelectrode 107 are not rounded.

The first pair of sides 108 of the electrode 107 is substantiallylinear, substantially parallel to each other and is approximately 1 cmin length. The second pair of sides 109 of the electrode 107 is alsosubstantially linear, substantially parallel with each other and isapproximately 5 cm in length. The bottom surface 115 of the electrode107 has an area of approximately 500 square mm. In alternativeembodiments, the first pair of sides 108 and the second pair of sides109 of the electrode 107 are neither linear nor parallel.

In alternative embodiments, the length of the first pair of sides 108and second pair of sides 109 of the electrode 107 range independentlybetween approximately 1 cm and approximately 5 cm. The surface area ofthe bottom surface 115 of the electrode 107 ranges between approximately100 sq. mm and approximately 2500 sq. mm. In one embodiment, the firstpair of sides 108 and second pair of sides 109 of the electrode 107 arelinear and have equal length, such that the electrode 107 issubstantially square-shaped.

The electrode 107 comprises a sheet of metallic mesh 114 furthercomprised of woven wires 119. The metallic mesh 114 comprises a metalselected from the group consisting essentially of titanium, nickelalloys, stainless steel alloys, platinum, platinum iridium, and mixturesthereof. In other embodiments, the metallic mesh 114 comprises anyconductive material.

In an alternate embodiment, the electrode 107 comprises a solid metallicplate. The metallic plate comprises a metal selected from the groupconsisting essentially of titanium, nickel alloys, stainless steelalloys, platinum, platinum iridium, and mixtures thereof. In otherembodiments, the solid plate comprises any conductive material.

The metallic mesh 114 is approximately a 150 mesh, having approximately150 individual wires 119 per inch. In alternative embodiments, themetallic mesh 114 ranges between approximately a 50 mesh andapproximately a 200 mesh. In this embodiment, the diameter of the wires119 of the mesh is approximately 1 mil. In alternative embodiments, thediameter of the wires 119 ranges between approximately 1 andapproximately 5 mils.

The metallic mesh 114 is first prepared by spot welding together thewires 119 located along the first pair of sides 108 and second pair ofsides 109 of the metallic mesh 114. The excess lengths of wires are thenground or machined flush, so as to produce a smooth edge and to form asmooth border 113. In an alternate embodiment, the wires 119 locatedalong the first pair of sides 108 and second pair of sides 109 of themetallic mesh 114 are bent in toward the metallic mesh 114 to form asmooth border 113.

The fin 120 is attached to the top surface 110 of the electrode 107 in aposition centered between the first pair of sides 108 of the electrode107. In other embodiments, the fin 120 is not centered between the firstpair of sides 108 of the electrode 107.

The fin 120 is a planar shape comprising a first face 191 and a secondface 192. The first face 191 and the second face 192 of the fin 120 aresubstantially parallel to the first pair of sides 108 of the electrode107. In other embodiments, the first face 191 and the second face 192 ofthe fin 120 are positioned in orientations other than parallel to thefirst pair of sides 108 of the electrode 107.

The first face 191 and the second face 192 of the fin 120 extend fromand substantially perpendicular to the top surface 110 of the electrode107. In an alternative embodiment, the first face 191 and the secondface 192 of the fin 120 extend from the top surface 110 of the electrode107 at other than right angles.

The fin core 122 of the fin 120 is spot welded to the metallic mesh 114comprising the electrode 107. In another embodiment, the fin 120 may becomposed entirely of a polymeric material and attached to the electrode107 by means known in the art.

FIG. 19( c) illustrates in detail a section of the lead 21 of thisembodiment. The lead 21 comprises an electrically insulating sheath 141and an electrical conductor 142.

The electrically insulating sheath 141 is disposed around the electricalconductor 142 (phantom view). The electrically insulating sheath 141prevents the cardioversion/defibrillation energy passing through theelectrical conductor 142 to the electrode from passing into objectssurrounding the lead 21. The electrically insulating sheath 141,comprises a tube 149 disposed around the electrical conductor 142. Thetube is composed of either silicone, polyurethane or compositematerials. One skilled in the art will recognize that the tube 149 couldalternately be composed of any insulating, flexible, bio-compatiblematerial suitable to this purpose.

In this embodiment, the electrical conductor 142 comprises threehighly-flexible, highly-conductive coiled fibers known as filars 147(phantom view). These fibers are wound in a helical shape through theelectrically insulating sheath 141. In an alternate embodiment, thefilars lie as linear cables within the electrically insulating sheath141. In another alternate embodiment, a combination of helically coiledand linear filars lies within the electrically insulating sheath 141.

FIG. 19( d) illustrates a cross-section of a filar 147. The filars 147of the embodiment illustrated comprise a metal core 144, a metal tube143 and an insulating coating 140. The metal tube 143 is disposed aroundthe metal core 144. The insulating coating 140 is disposed around themetal tube. The metal core 144 is made of silver and the metal tube 143is made of MP35N® stainless steel, a product of SPS Technologies ofJenkintown, Pa. The insulating coating 140 is made of Teflon. The filars147 of this structure are available as DFT™ (drawn filled tube)conductor coil, available from Fort Wayne Metals Research Products Corp.of Fort Wayne, Ind.

In an alternative embodiment, the filars 147 further comprise anintermediate coating (not shown) disposed between the metal tube 143 andthe insulating coating 140. This intermediate coating is made ofplatinum, iridium ruthenium, palladium or an alloy of these metals.

In another alternative embodiment, the filars 147 comprise DBS™ (drawnbraised strands) also available from Fort Wayne Metals Research ProductsCorp. of Fort Wayne, Ind.

Turning now to FIG. 19( e), a cross section of the lead fastener 146 isshown in detail. The lead fastener 146 provides a robust physical andelectrical connection between the lead 21 and the electrode 107.

In this embodiment, the lead fastener 146 comprises a metal strip 157, acrimping tube 154 and a crimping pin 156. The metal strip 157 has afirst end 150, a second end 151, and a middle portion 152. The first end150 and second end 151 of the metal strip 157 are separated by themiddle portion 152. The first end 150 and second end 151 of the metalstrip 157 are attached to the electrode 107. In this embodiment, thefirst end 150 and second end 151 of the lead fastener 146 are spotwelded to the top surface 110 of the metallic mesh 114 comprising theelectrode 107. In other embodiments, other fastening methods known inthe art can be used.

The middle portion 152 of the metal strip 157 is raised away from theelectrode 107 to permit the crimping tube 154 and electricallyinsulating sheath 141 of the lead 21 to fit between the metal strip 157and the electrode 107.

The middle portion 152 of the metal strip 157 contains a crimp point148. The crimp point 148 squeezes the crimping tube 154 and electricallyinsulating sheath 141 of the lead 21 thereby gripping it, and therebyproviding a robust structural connection between the lead 21 and theelectrode 107.

The filars 147 of the lead 21 are situated between the crimping tube 154and crimping pin 156. The crimping tube 154 has a crimping point 155which causes the filars 147 to be squeezed between crimping tube 154 andcrimping pin 156. A gap 159 in the electrically insulating sheath 141allows the crimping tube 155 to make contact the electrode 107, therebyforming a robust electrical connection.

The metal strip 157, the crimping tube 154 and crimping pin 156 are eachmade of platinum iridium. In an alternative embodiment, the metal strip157, crimping tube 154 and crimping pin 156 are each made of a metalselected from the group consisting essentially of titanium, nickelalloys, stainless steel alloys, platinum, platinum iridium, and mixturesthereof. In an alternative embodiment, the metal strip 157, crimpingtube 154 and crimping pin 156 are each made of any conductive material.

FIG. 19( f) illustrates an exploded view of the lead fastener 146. Inother embodiments, other types of lead fasteners 146 known in the artare used.

FIG. 20( a) illustrates an alternative embodiment of the lead electrodeassembly 100. This embodiment is substantially similar to the leadelectrode assembly 100 illustrated in FIGS. 19( a)-19(f). In thisembodiment, however, the appendage 118 lacks a fin core 122. Moreover,as seen in FIG. 20( a) the lead electrode assembly 100 of thisembodiment further comprises a backing layer 130 and stitching 139. Thebacking layer 130 acts to insulate the electrode 107 so thatcardioversion/defibrillation energy may not pass to the tissue of thepatient that surrounds the top surface 110 of the electrode 107. Thishas the effect of focusing the cardioversion/defibrillation energytoward the heart of the patient through the bottom surface 115 of theelectrode 107.

The backing layer 130 comprises a base portion 158 and an integrated fin120. The base portion 158 of the backing layer 130 comprises a firstsurface 131, a second surface 132, a first side 133 and a second side134.

The base portion 158 of the backing layer 130 is attached to theelectrode 107 such that the second surface 132 of the backing layer 130lies directly adjacent to the top surface 110 of the electrode 107.

The base portion 158 of the backing layer 130 is formed so that thefirst side 133 and the second side 134 are substantially parallel and ofsubstantially the same size as the first pair of sides 108 of theelectrode 107.

FIG. 20( b) illustrates a top view of the lead electrode assembly 100 ofthis embodiment. The base portion 158 of the backing layer 130 furthercomprises a distal end 137 and a proximal end 138.

The distal end 137 and proximal end 138 of the backing layer 130 areparallel to and of substantially the same size as the second pair ofsides 109 (hidden) of the electrode 107. The backing layer 130 containsa notch 136 on its distal end 137, through which the lead fastener 146rises.

The base portion 158 of the backing layer 130 is attached to theelectrode 107 with stitching 139. The stitching is composed of nylon. Inalternate embodiments, the stitching is composed of any polymericmaterial.

The backing layer 130 is composed of polyurethane. In an alternativeembodiment, the backing layer is composed of molded silicone, nylon, orDacron®. In alternative embodiments, the backing layer is composed ofany polymeric material.

The integrated fin 120 of the backing layer 130 is formed from the samepiece of material as the backing layer 130. The integrated fin 120 hasthe same shape and dimensions as the fin 120 of the embodiment in FIG.19( b).

In one embodiment, the integrated fin 120 is reinforced with a layer ofDacron® polymer mesh attached to the integrated fin 120. In anotherembodiment, the integrated fin 120 is reinforced with a layer of anypolymeric material.

FIG. 21( a) illustrates an alternative embodiment of the lead electrodeassembly 100. This embodiment is substantially similar to the leadelectrode assembly 100 illustrated in FIGS. 19( a)-19(e). In thisembodiment, however, the fin 120 has a different construction.

Here, fin 120 comprises a first fin section 165, a second fin section160 and stitching 168. The first fin section 165 is a rectangular sheetof polymeric material comprising an inside face 167, an outside face166, a first side 175 and a second side 174. The first side 175 andsecond side 174 of the first fin section 165 are substantially paralleland of substantially the same size.

A line 173 divides the first fin section 165 into a first half 171 and asecond half 172. The line 173 runs parallel to the first side 175 of thefirst fin section 165. The first half 171 of the first fin section 165lies on one side of line 173. The second half 172 of the first finsection 165 lies on the other side of the line 173.

The second fin section 160 is a rectangular sheet of polymeric materialof the same size as the first fin section 165 comprising an inside face162 and an outside face 161. The second fin section 160 is divided inhalf substantially similarly to the first fin section 165, therebyforming a first half 163 and a second half 164 of the second fin section160.

In an alternate embodiment, the first fin section 165 and second finsection are not rectangular in shape. In an alternate embodiment, thefirst fin section 165 and second fin section have an oval shape.

The first half 171 of the first fin section 165 is fastened to the firsthalf 163 of the second fin section 160. The inside face 167 of the firsthalf 171 of the first fin section 165 faces the inside face 162 of thefirst half 163 of the second fin section 160. The first fin section 165is fastened the second fin section 160 with stitching 168.

The fin 120 is attached to the top surface 110 of the electrode 107. Toaccomplish this, the second half 172 of the first fin section 165 isattached to the top surface 110 of the electrode 107 with the stitching169. The second half 164 of the second fin section 160 is similarlyattached to the top surface 110 of the electrode 107 with stitching (notshown).

In one embodiment, the fin 120 is reinforced with a layer of Dacron®polymer mesh positioned between the first fin section 165 and the secondfin section 160 of the integrated fin 120. In another embodiment, theDacron® polymer mesh is attached only to the first fin section 165 orthe second fin section 160. In other embodiments, the integrated fin 120is reinforced with a layer of any polymeric material attached to eitheror both fin sections.

The appendage height of the fin 120 in this embodiment is approximately5 mm. In alternative embodiments, the appendage heights range betweenapproximately 1 mm and approximately 10 mm. The appendage length of thefin 120 in this embodiment is approximately 1 cm. In alternativeembodiments, appendage lengths range between approximately 2 mm andapproximately 6 cm. In one embodiment, the appendage length of the fin120 is such that the fin 120 is substantially as long as the electrode107.

FIG. 22( a) illustrates a side plan view of an alternative embodiment ofthe lead electrode assembly 100. The lead electrode assembly 100comprises a connector 111, a lead 21, a lead fastener 146, an electrode107, a backing layer 130 with an integrated fin tab 180, a molded cover220 and an appendage 118.

The connector 111 is connected to the lead 21. The lead 21 is furtherconnected to the electrode 107 with the lead fastener 146. The backinglayer 130 is positioned over the electrode 107. The fin tab 180protrudes from the backing layer 130. The molded cover 220 is disposedaround the lead fastener 146 and the backing layer 130. The molded cover220 is further disposed around the fin tab 180 of the backing layer 118to form the appendage 118. The molded cover 220 also partially envelopsthe electrode 107.

The connector 111 and the lead 21 are substantially similar to theconnector 111 and the lead 21 described with reference to FIGS. 19(a)-19(f). The lead comprises a distal end 101 and a proximal end 102.The distal end 101 of the lead 21 is attached to the connector 111. Theproximal end 102 of the lead 21 is connected to the electrode 107 by thelead fastener 146.

In this embodiment, the lead fastener 146 comprises a first crimpingtube 200, a crimping pin 202 and a second crimping tube 201. The firstcrimping tube 200 connects the proximal end 102 of the lead 21 to thecrimping pin 202. The second crimping tube 201 connects the crimping pin202 to the electrode 107.

The electrode 107 comprises a distal end 103 (phantom view), a proximalend 104, a top surface 110 and a bottom surface 115. The electrodefurther comprises three sections: a main body 217, a mandrel 219 and amandrel neck 218.

The main body 217 of the electrode 107 is the region of the electrode107 that makes contact with the tissue of the patient and transfers thecardioversion/defibrillation energy to the patient. This region issubstantially rectangular, comprising a first pair of sides 108 (notshown) and a second pair of sides 109. The first pair of sides 108 ofthe electrode 107 is substantially parallel to each other. The secondpair of sides 109 of the electrode 107 is also substantially parallel toeach other. In another embodiment, the first pair of sides 108 and thesecond pair of sides 109 of the electrode 107 are non-parallel. The mainbody 217 of the electrode 107 is positioned under the backing layer 130,so that the top surface 110 of the electrode faces the backing layer130.

The mandrel 219 is a region of the electrode 107 shaped to facilitatethe connection of the electrode 107 to the lead 21 via the lead fastener146. The mandrel of the electrode is crimped onto to the crimping pin202 of the lead fastener 146 with the second crimping tube 201, so thata robust physical and electrical connection is formed. The main body 217of the electrode 107 is connected to the mandrel 219 of the electrode107 via the mandrel neck 218 of the electrode 107.

The backing layer 130 comprises a base portion 158 and an integrated fintab 180. The base portion 158 of the backing layer 130 comprises a firstsurface 131, a second surface 132, a distal end 137 and a proximal end138.

The base portion 158 of the backing layer 130 is positioned such thatits second surface 132 is adjacent to the top surface 110 of theelectrode 107. The base portion 158 of the backing layer 130 is sizedand positioned so that the distal end 137 and proximal end 138 of thebase portion 158 of the backing layer 130 overlay the second pair ofsides 109 of the main body 217 of the electrode 107. The distal end 137and proximal end 138 of the base portion 158 of the backing layer 130are also substantially parallel and of substantially the same size asthe second pair of sides 109 of the electrode 107.

The integrated fin tab 180 of the backing layer 130 is formed from thesame piece of material as the base portion 158 of the backing layer 130.The integrated fin tab 180 is formed on the first surface 131 of thebase portion 158 of the backing layer 130.

The integrated fin tab 180 comprises a proximal edge 183, a distal edge184, a top 185 and a bottom 186. The bottom 186 of the integrated fintab 180 is joined to the first surface 131 of the base portion 158 ofthe backing layer 130. The proximal edge 183 and the distal edge 184 ofthe integrated fin tab 180 extend from, and substantially perpendicularto the first surface 131 of the base portion 158 of the backing layer130. The proximal edge 183 and distal edge 184 of the integrated fin tab180 are parallel with each other. The integrated fin tab 180 ispositioned so that its proximal edge 183 is substantially flush with theproximal end 138 of the base portion 158 of the backing layer 130.

The backing layer 130 is composed of polyurethane. In an alternativeembodiment, the backing layer 130 is composed of silicone. In anotheralternative embodiment, the backing layer 130 is composed of anypolymeric material.

The molded cover 220 envelops and holds together the components of thelead electrode assembly 100. The molded cover 220 also provides rigidityto the lead electrode assembly 100. The molded cover 220 envelops thelead fastener 146 and the backing layer 130. The fin 120 is formed whenthe molded cover 220 covers the fin tab 180. The thickness of theresulting fin 120 is approximately 2 mm. In alternate embodiments, thethickness of the fin 120 is between approximately 1 mm and approximately3 mm.

The appendage height of the fin 120 in this embodiment is approximately5 mm. In alternative embodiments, the appendage heights range betweenapproximately 1 mm and approximately 10 mm. The appendage length of thefin 120 in this embodiment is approximately 1 cm. In alternativeembodiments, appendage lengths range between approximately 2 mm andapproximately 6 cm. In one embodiment, the appendage length of the fin120 is such that the fin is as long as the backing layer. In oneembodiment, the appendage length of the fin 120 is such that the fin isas long as the electrode 107. In one embodiment, the appendage length ofthe fin 120 is such that the fin is as long as the molded cover 220.

The molded cover 220 also partially covers the bottom surface 115 of theelectrode 107. In this way, the molded cover 220 attaches the backinglayer 130 to the electrode 107.

The molded cover 220 in this embodiment is made of silicone. In analternate embodiment, the molded cover 220 is made of any polymericmaterial. Stitching 360 holds the molded cover 220, the electrode 107and the backing layer 130 together.

In one embodiment, the fin 120 is reinforced with a layer of Dacron®polymer mesh positioned between the molded cover 220 and the integratedfin tab 180. In another embodiment, the Dacron® polymer mesh is attachedonly to the molded cover 220. In other embodiments, the fin 120 issimilarly reinforced with a layer of any polymeric material.

As shown in FIG. 22( b), the fin 120 of the embodiment illustrated inFIG. 22( a) can alternately have a sloped shape. The sloped shape canreduce the resistance offered by the tissue of the patient as it slidesagainst the fin 120 during the insertion of the lead electrode assembly100 into the patient. The slope-shaped fin 120 is constructed so thatthe proximal edge 183 and distal edge 184 of the integrated fin tab 180are not parallel with each other. Instead, proximal edge 183 of theintegrated fin tab 180 can be curved so that the proximal edge 183 ofthe integrated fin tab 180 is closer to the proximal edge 184 at the top185 of the integrated fin tab 180, than at the bottom 186 of theintegrated fin tab 180. In alternate embodiments, the proximal edge 183of the integrated fin tab 180 is not curved. Instead, the proximal edge183 of the integrated fin tab 180 is straight, and forms an acute anglewith the first surface 131 of the backing layer 130. In one alternateembodiment, the proximal edge 183 of the integrated fin tab 180 forms a45 degree angle with the first surface 131 of the backing layer 130. Inalternate embodiments, the distal edge 184 of the integrated fin tab 180is curved. In alternate embodiments, the distal edge 184 of theintegrated fin tab 180 is straight and shaped so that it forms an acuteangle with the first surface 131 of the backing layer 130.

FIG. 22( c) illustrates a front plan view of the lead electrode assembly100 seen in FIG. 22( a). The base portion 158 of the backing layer 130further comprises a first side 133 and second side 134. The first side133 and second side 134 of the base portion 158 of the backing layer 130are substantially parallel. In an alternate embodiment, the first side133 and second side 134 of the backing layer 130 are not parallel. Thebase portion 158 of the backing layer 130 is sized so that it issubstantially the same size and shape as the main body 217 of theelectrode 107.

The integrated fin tab 180 of the backing layer 130 is planar,comprising a first face 181 and a second face 182. The first face 181and second face 182 of the fin tab 180 are substantially parallel witheach other and with the first side 133 and second side 134 of thebacking layer 130. The first face 181 and second face 182 of the fin tab180 extend from, and substantially perpendicular to the first surface131 of the backing layer 130. In another embodiment, the first face 181and second face 182 of the fin tab 180 extend from the first surface 131of the backing layer 130 at angles other than a right angle.

In an alternate embodiment, the first face 181 and a second face 182 ofthe integrated fin tab 180 of the backing layer 130 are notsubstantially parallel to each other. Instead, they are angled, suchthat they are closer together at the top 185 than they are at the bottom186 of the integrated fin tab 180. This shape can reduce the resistanceoffered by the tissue of the patient as it slides against the fin 120during the insertion of the lead electrode assembly 100 into thepatient.

In another embodiment, the first face 181 and a second face 182 of theintegrated fin tab 180 of the backing layer 130 are angled, such thatthey are further apart at the top 185 than they are at the bottom 186 ofthe integrated fin tab 180. This shape can make the fin 120 easier togrip with a tool, such as a hemostat.

The fin tab 180 extends from the backing layer 130 at a positioncentered between the first side 133 and the second side 134 of thebacking layer 130. In an alternate embodiment, the fin tab 180 is notcentered between the first side 133 and the second side 134 of thebacking layer 130.

An eyelet 301 is formed in the fin 120 of this embodiment. The eyeletcan be used to facilitate the capture of the lead electrode assembly bya tool. The eyelet is formed as a hole 225 through the molded cover 220and between the faces 181 and 182 of fin tab 180. In an alternateembodiment, no eyelet is formed in the fin 120.

The bottom surface 115 of the electrode 107 comprises a periphery 213and a center 211. The molded cover 220 forms a skirt 222 around theperiphery 213 of the bottom surface 115 of the electrode 107. The skirt222 of the molded cover 220 covers the periphery 213 of the bottomsurface 115 of the electrode 107.

The skirt 222 of the molded cover 220 can act to focuscardioversion/defibrillation energy emitted from the electrode 107 ofthe lead electrode assembly 100 toward the heart of the patient. Becausethe thorax of a patient is surrounded by a layer of fat that is somewhatconductive, the cardioversion/defibrillation energy may tend to arcthrough this layer to reach the active surface 15 of the canister 11(seen in FIG. 1) without passing through the patient's heart. The skirt222 of the lead electrode assembly 100 acts to minimize the loss ofcardioversion/defibrillation energy to surrounding body tissues, or frombeing diverted away from the patient's heart.

The center 211 of the bottom surface 115 of the electrode 107 is notcovered by the molded cover 220 and is left exposed. The width of theperiphery 213 of the bottom surface 115 of the electrode 107 covered bythe molded cover 220 is approximately 0.125 cm.

The area of the exposed center 211 of the bottom surface 115 of theelectrode 107 is approximately 500 square mm. In alternativeembodiments, the length of the first pair of sides 108 and the secondpair of sides 109 of the electrode 107 varies, such that the area of thecenter 211 of the bottom surface 115 of the electrode has a surface areabetween approximately 100 sq. mm. and approximately 2500 sq. mm.

FIG. 22( d) illustrates an exploded top view of the lead fastener 146 ofthe embodiments illustrated in FIGS. 22( a)-22(c). The lead fastenerconnects the proximal end 102 of the lead 21 and the distal end 103 ofthe electrode 107.

In this embodiment, the lead fastener 146 comprises a first crimpingtube 200, a crimping pin 202 and a second crimping tube 201. Thecrimping pin 202 comprises a first side 203 and a second side 204.

The crimping tube 200 crimps the filars 147 of the lead 21 (here, onlyone representative filar 147 is shown) to the first side 203 of crimpingpin 202. The mandrel 219 of the electrode 107 is then wrapped around thesecond side 204 of the crimping pin 202. Crimping tube 201 crimps themandrel 219 to the second side 204 of the crimping pin 202.

The first crimping tube 200, the second crimping tube 201 and thecrimping pin 202 are each made of platinum iridium. In an alternativeembodiment, the first crimping tube 200, the second crimping tube 201and the crimping pin 202 are each made of a metal selected from thegroup consisting essentially of titanium, nickel alloys, stainless steelalloys, platinum, platinum iridium, and mixtures thereof. In otherembodiments, the first crimping tube 200, the second crimping tube 201and the crimping pin 202 each comprise any conductive material.

The electrode 107 in this embodiment comprises a sheet of metallic mesh206 prepared by the process described with reference to FIG. 19( b). Theelectrode 107 has a width measured parallel to the second pair of sides109 of the electrode 107. The width of the mandrel neck 218 of theelectrode 107 is approximately 3 mm wide. The width of the mandrel ofthe electrode 107 is approximately 5 mm wide.

The first pair of sides 108 of the electrode 107 is approximately 5 cmin length. The second pair of sides 109 of the electrode 107 isapproximately 1.9 cm in length. In alternative embodiments, the lengthof the first pair of sides 108 and the second pair of sides 109 of theelectrode 107 ranges independently from approximately 1 cm toapproximately 5 cm.

The electrode 107 of this embodiment further comprises four corners 112.The corners 112 of the electrode 107 are rounded. In an alternateembodiment, the corners 112 of the electrode 107 are not rounded.

FIGS. 22( e)-22(g) illustrate the size and position of the fin 120 onthe molded cover of the lead electrode assembly 100.

FIGS. 23( a)-23(c) illustrate an alternative embodiment of the leadelectrode assembly 100. This embodiment is substantially similar to theembodiments illustrated in FIGS. 22( a)-22(g). In this embodiment,however, the appendage height of the fin 120 is approximately 1 cm. Theappendage length of the fin 120 in this embodiment is approximately 3.5cm.

As shown in FIG. 23( a), stitching 302 is placed through the moldedcover 220 and the fin 120 to prevent the molded cover 220 from slidingoff the fin tab 180 when the molded cover 220 is subjected to a forcedirected away from the electrode 107.

As shown in FIG. 23( c), the fin 120 (phantom view) extendsapproximately two thirds of the length of the electrode 107.

FIG. 24 illustrates an alternative embodiment of the lead electrodeassembly 100. This embodiment is substantially similar to theembodiments illustrated in FIGS. 22( a)-22(g). In this embodiment,however, the backing layer 130 (not shown) inside the molded cover 220is curved. This results in an electrode 107 that has a curvature ofradius r, such that the bottom surface 115 of the electrode 107 isconcave.

Because a curved electrode 107 may more closely approximate thecurvature of the patient's ribs, this curvature may have the effect ofmaking the lead electrode assembly 100 more comfortable for the patient.In one embodiment, the radius r of the curvature varies throughout theelectrode 107 such that it is intentionally shaped to approximate theshape of the ribs. Lead electrode assemblies 100 can be custommanufactured with an electrode 107 with a curvature r that matches thecurvature of the intended patient's ribcage in the vicinity of theribcage adjacent to which the electrode 107 is to be positioned.

In an alternative embodiment, lead electrode assemblies 100 aremanufactured with an electrode 107 with a radius r that matches thecurvature of the ribcage of a statistically significant number ofpeople.

In another embodiment, lead electrode assemblies 100 with electrodes 107of varying curvatures can be manufactured to allow an electrode radius rto be selected for implantation based on the size of the patient.Smaller radii can be used for children and for smaller adult patients.Larger radii can be used for larger patients. The radius r of thecurvature can range from approximately 5 cm to approximately 35 cmdepending on the size of the patient.

In an alternative embodiment, the electrode 107 of the lead electrodeassembly 100 is flexible, such that it can be bent to conform to thecurvature of the intended patient's rib cage at the time ofimplantation.

FIGS. 25( a)-25(c) illustrate an alternative embodiment of the leadelectrode assembly 100. This embodiment is substantially similar to theembodiments illustrated in FIGS. 22( a)-22(g). In this embodiment,however, the backing layer 130 lacks an integrated fin tab 180 mountedon the first surface 131 of the backing layer 130. Moreover, thisembodiment further comprises a backing layer 400 having a fin tab 405.

FIGS. 25( a) and 25(b) illustrate only the backing layer 400, the fintab 405 and the electrode 107 of this embodiment as they are positionedrelative to each other in the complete embodiment. Other components ofthe embodiment are not shown. FIG. 25( c) shows the embodiment in acomplete form.

FIG. 25( a) illustrates a top plan view of the backing layer 400 and theelectrode 107. The backing layer 400 is positioned over the electrode107. The electrode 107 of this embodiment is substantially similar tothe electrode 107 of the embodiment illustrated in FIG. 22( d). In thecomplete embodiment, the mandrel 219 of the electrode 107 is joined tothe lead 21 (not shown) by a lead fastener 146 (not shown) as shown inFIG. 22( a).

The backing layer 400 is a flat, planar member comprising a distal end137 and a proximal end 138. The backing layer 400 further comprises afirst side 133, a second side 134, a first surface 131, and a secondsurface 132 (not shown). The backing layer 400 further comprises awidth, W, measured as the distance between the first side 133 and thesecond side 134.

The backing layer 400 includes a fin tab 405 that is formed from thesame piece of material as the backing layer 400. The first side 133 ofthe backing layer 400 lies over one of the first pair of sides 108 ofthe electrode 107 except over a fin tab region 407. In the fin tabregion 407, the backing layer 400 is wider than the electrode 107. Inthe fin tab region 407, the first side 133 forms a fin tab 405 thatprotrudes from part of the first side 133 of the backing layer 400outside the fin tab region 407. The fin tab 405 extends from the firstside 133 of the backing layer 400 in an orientation substantiallyparallel to the top surface 110 of the electrode 107, beyond the firstside 108 (phantom view) of the electrode 107.

The fin tab 405 comprises a first face 410 and a second face 411 (notshown). The first face 410 of the fin tab 405 is an extension of thefirst surface 131 of the backing layer 400. The second face 411 of thefin tab 405 is an extension of the second surface 132 of the backinglayer 400.

Aside from the fin tab 405, the backing layer 405 is formed so that itis of substantially the same size and shape as the main body 217 of theelectrode 107.

The backing layer 400, including the fin tab 405, is composed ofpolyurethane. In an alternate embodiment, the backing layer 400 and fintab 405 are composed of any polymeric material.

FIG. 25( b) is a side plan view of the backing layer 400 and theelectrode 107. The backing layer 400 is positioned over the electrode107 such that the second surface 132 of the backing layer 400 is placedadjacent to the top surface 110 of the electrode 107.

FIG. 25( c) illustrates a bottom plan view of the complete embodiment,in which the backing layer 400 (not shown), the lead fastener 146 (notshown) and the fin tab 405 (phantom view) are coated with a molded cover220. When the molded cover 220 is applied over the backing layer 400, afin 424 is formed over the fin tab 405 (phantom view). The fin 424comprises a proximal end 404 and a distal end 403.

In one embodiment, the fin 424 is reinforced with a layer of Dacron®polymer mesh positioned between the molded cover 220 and the fin tab405. In another embodiment, the Dacron® polymer mesh is attached only tothe molded cover 220. In other embodiments, the fin 424 is similarlyreinforced with a layer of any polymeric material.

The appendage height, h_(Appendage), of the fin 424 of this embodimentis approximately 5 mm. In alternative embodiments, the appendage heightsrange between approximately 1 mm and approximately 10 mm. The appendagelength, L_(Appendage), of the fin 424 of this embodiment is measuredbetween the proximal end 404 and the distal end 403 of the fin 424.L_(Appendage) is measured where the fin 424 joins the rest of the leadelectrode assembly 100. In this embodiment, the appendage length isapproximately 1 cm. In alternative embodiments, the appendage lengthsrange between approximately 2 mm and approximately 6 cm. In oneembodiment, the appendage length of the fin 424 is such that the fin 424runs the length of the electrode 107. In one embodiment, the appendagelength of the fin 424 is such that the fin 424 runs the length of thebacking layer 130 (not shown). In one embodiment, the appendage lengthof the fin 424 is such that the fin 424 runs the length of the moldedcover 220.

FIG. 25( d) illustrates a bottom plan view of an alternate embodiment ofthe lead electrode assembly 100. This embodiment is substantiallysimilar to the lead electrode assembly 100 illustrated in FIGS. 25(a)-25(c). In this embodiment, however, proximal end 404 of the fin 424is sloped. The sloped shape of the fin 424 is formed by the shape of thefin tab 405 (phantom view) inside the fin 424. The backing layer 400gradually widens in the fin tab region 407 (not shown) with distancefrom the proximal end 138 (not shown) to the distal end 137 (not shown)of the backing layer 130 (not shown) until the appendage height isreached. The proximal end 404 of the fin 424 is straight and forms anacute angle with the first side 133 of the base portion 158 of thebacking layer 130 (not shown). In an alternate embodiment, the proximalend 404 of the fin 424 forms a 45 degree angle with the first side 133of the base portion 158 of the backing layer 130 (not shown). In anotherembodiment, the proximal end 404 of the fin 424 is curved slope.

In alternate embodiments, the distal end 403 of the fin 424 is straightand shaped so that it forms an acute angle with the first side 133 ofthe base portion 158 of the backing layer 130 (not shown). In alternateembodiments, the distal end 403 of the fin 424 is curved.

FIGS. 26( a)-26(c) illustrate an alternative embodiment of the leadelectrode assembly 100. This embodiment is substantially similar to theembodiment illustrated in FIGS. 20( a)-20(b). The integrated fin 120 isabsent, however, from the backing layer 130.

The lead electrode assembly 100 of this embodiment further comprises acylindrical rod 500 having a loop 515 formed therein. The loop 515comprises the appendage 118 of this embodiment. The loop 515 is a memberattached to the electrode 107 that can be gripped and used to preciselylocate the electrode 107 during its surgical implantation within thepatient.

FIG. 26( a) illustrates a side plan view of the embodiment. Thecylindrical rod 500 comprises a first straight portion 510, a secondstraight portion 512 and a portion formed into a loop 515. The firststraight portion 510 is separated from the second straight portion 512by the loop 515.

The rod 500 is made of platinum iridium. In an alternative embodiment,the rod 500 is made of titanium or platinum.

The first straight portion 510 and second straight portion 512 are spotwelded to the top surface 110 of the electrode 107. The loop 515 in therod 500 extends away from the top surface 110 of the electrode 107.

The backing layer 130 is similar to the backing layer 130 illustrated inFIGS. 20( a)-20(b). The backing layer 130 is disposed over the electrode107. The first straight portion 510 and second straight portion 512 ofthe rod 500 are positioned between the second surface 132 of the backinglayer 130 and the top surface 110 of the electrode 107.

FIG. 26( b) illustrates a cross-sectional rear plan view of theembodiment of the lead electrode assembly shown in FIG. 26( a). Thefirst straight portion 510 and second straight portion 512 arepositioned such that they are parallel to the first pair of sides 108 ofthe electrode 107. The first straight portion 510 and second straightportion 512 are both centered between the first pair of sides 108 of theelectrode 107. In an alternative embodiment, the first straight portion510 and second straight portion 512 are not parallel to and centeredbetween the first pair of sides 108 of the electrode 107.

FIG. 26( c) illustrates a top plan view of the embodiment of the leadelectrode assembly shown in FIG. 26( a). An aperture 517 is formed inthe backing layer 130. The aperture 517 in the backing layer ispositioned such that the loop 515 extends through and beyond theaperture 517 in a direction away from the top surface 110 of theelectrode 107. The backing layer 130 is attached to the electrode 107with stitching 139.

FIGS. 27( a)-27(d) illustrate an alternative embodiment of the leadelectrode assembly 100. This embodiment is substantially similar to theembodiment illustrated in FIGS. 20( a)-20(b). This embodiment comprisesa backing layer 610, however, that lacks the integrated fin 120illustrated in FIGS. 20( a)-20(b).

FIG. 27( a) illustrates a top plan view of the backing layer 610 of thisembodiment prior to its attachment to the rest of the lead electrodeassembly 100. The backing layer 610 is cut in a pattern as shown. Thebacking layer comprises a first surface 131, a second surface 132 (notshown), a distal end 137, a proximal end 138, a first side 133, a secondside 134 and an indented fin-forming region 620. The indentedfin-forming region 620 comprises a first edge 690 and a second edge 691.

The backing layer 610 is formed so that the first side 133 and thesecond side 134 are substantially parallel and of substantially the samesize as the first pair of sides 108 of the electrode 107. The proximalend 138 is formed so that it is substantially perpendicular to the firstside 133 and the second side 134 of the backing layer 610. The proximalend 138 is longer than the second pair of sides 109 of the electrode 107by a length A. The backing layer 610 has a varying width C measured fromits distal end 137 to its proximal end 138 along a line parallel to itsfirst side 133.

The backing layer is divided into three sections. A first backingsection 693, a second backing section 692 and an indented fin-formingregion 620 of length A. The length of the fin-forming region 620, A, isapproximately 10 mm. In other embodiments, the length of the fin-formingregion 620, A, ranges between approximately 2 mm and approximately 20mm.

The area within the indented fin-forming region 620 is equally dividedinto a first fin area 612 and a second fin area 615. The dividing line617 between the first fin area 612 and the second fin area 615 issubstantially parallel to the first side 133.

The width, C, of the backing layer 610 is equal to the distance betweenthe second pair of sides 109 of the electrode 107 except in the indentedfin-forming region 620. In the indented fin-forming region 620, thewidth, C, of the backing layer 610 is B. The width, B, of the backinglayer 610 in the fin-forming region 620, is approximately 1 cm. Inalternate embodiments, the width, B, of the backing layer 610 in thefin-forming region 620 ranges between approximately 2 mm andapproximately 6 cm. In other embodiments, however, the fin-formingregion 620 ranges between 2 mm and the width, C, of the backing layer610. In other embodiments, the fin-forming region 620 is longer than thewidth, C, of the backing layer 610.

The variation in width between the areas inside and outside the indentedfin-forming region 620 forms the first edge 690 and a second edge 691 ofthe fin-forming region 620.

A first notch 136(a) is formed on the distal end 137 the first edge 690of the fin-forming region 620 of the backing layer 130. A second notch136(b) is formed on the distal end 137 the second edge 691 of thefin-forming region 620 of the backing layer 130.

The backing layer 610 in this embodiment is formed of flexible silicone.In alternative embodiments the backing layer 610 is formed of anybio-compatible, flexible polymeric material.

FIG. 27( b) illustrates a top plan view of the lead electrode assembly100 of this embodiment. The backing layer 610 is attached to theelectrode 107, so that the first edge 690 and a second edge 691 of thefin-forming region 620 of the backing layer 610 meet. This causes thebacking layer 610 in the first fin area 612 and the second fin area 615to fold together to form a fin 120.

The first notch 136(a) and second notch 136(b) formed on the distal end137 the first edge 690 and second edge 691 of the fin-forming region 620of the backing layer 130 meet to form a notch 136 on the distal end 137of the backing layer, through which the lead fastener 146 rises.Stitching 660 holds the backing layer to the electrode 107.

FIG. 27( c) illustrates a side plan view of the lead electrode assembly100 of this embodiment. Stitching 660 holds the first fin area 612 and asecond fin area 615 of the backing layer 610 together to form the fin120.

FIG. 27( d) illustrates a front plan view of the lead electrode assembly100 of this embodiment. In one embodiment, the fin 120 is reinforcedwith a layer of Dacron® polymer mesh positioned between the first finarea 612 and a second fin area 615. In another embodiment, the Dacron®polymer mesh is attached only to either first fin area 612 or the secondfin area 615. In other embodiments, the fin 120 is similarly reinforcedwith a layer of any polymeric material.

FIGS. 27( e) and 27(f) illustrate an alternative embodiment of the leadelectrode assembly 100. This embodiment is substantially similar to theembodiment illustrated in FIGS. 27( a)-27(d). The backing layer 610 issubstantially similar to the backing layer 610 illustrated in FIG. 27(a). The backing layer 610 in this embodiment, however, is cut along line617. The fin 120 of this embodiment comprises a proximal edge 129. Theproximal edge 129 of the fin 120 is slope-shaped. The sloped shape canreduce the resistance offered by the tissue of the patient as it slidesagainst the fin 120 during the insertion of the lead electrode assembly100 into the patient.

FIGS. 28( a) and 28(b) illustrate a property of the embodiment of thelead electrode assembly 100 illustrated in FIGS. 27( e) and 27(f). Thebacking layer 610 is flexible, such that the substantially planar fin120 formed therefrom is flexible and able to fold. Because the abilityof the fin 120 to fold effectively reduces its appendage height, it maymake the fin more comfortable to the patient after it is implanted.

FIG. 28( a) shows fin 120 in an upright condition. When pressure isapplied perpendicular to the first surface 131 of backing layer in thefirst fin area 612, along line 677 for example, the fin 120 folds asshown in FIG. 28( b). When the fin 120 folds, its appendage height,H_(Appendage), is reduced. This can be seen by a comparison between FIG.28( a) and FIG. 28( b).

The backing layer 610 in this embodiment is formed of a polymericmaterial. In an alternative embodiment, the backing layer 610 is formedof any bio-compatible, flexible polymeric material.

FIGS. 29( a)-29(c) illustrate an alternative embodiment of the leadelectrode assembly 100. This embodiment is substantially similar to theembodiment illustrated in FIGS. 27( a)-27(d).

As shown in FIG. 29( a), however, the material from the first fin area612 and the second fin area 615 of the backing layer 610 is not fastenedtogether with stitching 660 in this embodiment. The resulting appendage118 is formed in the shape of a tube.

In alternate embodiments, the backing layer 610 is coupled to theelectrode 107 such that the material from the first fin area 612 and thesecond fin area 615 of the backing layer 610 does not touch except atthe dividing line 617 between the first fin area 612 and the second finarea 615. The separation between the first fin area 612 and the secondfin area 615 of the backing layer 610 can allow the appendage 118 ofthis embodiment to be highly flexible. This flexibility can reduce theresistance offered by the tissue of the patient as it slides against theappendage 118 during the insertion of the lead electrode assembly 100into the patient.

FIG. 29( b) illustrates a side plan view of the embodiment illustratedin FIG. 29( a). The appendage 118 of this embodiment comprises aproximal edge 129. The proximal edge 129 of the appendage 118 isslope-shaped. The sloped shape can reduce the resistance offered by thetissue of the patient as it slides against the appendage 118 during theinsertion of the lead electrode assembly 100 into the patient.

In alternate embodiments, the proximal edge 129 of the tube formed bythe appendage 118 is closed. In one embodiment, the proximal edge 129 ofthe appendage 118 is closed by a cap (not shown). In another embodiment,the proximal edge 129 of the appendage 118 is closed with stitchingplaced between the first fin area 612 and the second fin area 615 onlyat the proximal edge 129 of the appendage 118. In another embodiment,the proximal edge 129 of the appendage 118 is closed by any other meansknown in the art for this purpose.

FIG. 29( b) illustrates a top plan view of the embodiment illustrated inFIGS. 29( a)-29(b).

FIGS. 30( a)-30(d) illustrate an alternative embodiment of the leadelectrode assembly 100. This embodiment is substantially similar to theembodiment illustrated in FIGS. 20( a)-20(b). The backing layer 130 ofthis embodiment, however, lacks an integrated fin 120.

FIG. 30( a) illustrates a front plan view of the lead electrodeassembly. The fin 120 in this embodiment comprises a fin head 700 andflexible joining material 702.

The fin head 700 comprises a rectangular sheet having a first face 705,a second face 706, a first end 710 and a second end 712. The fin head700 further comprises a height measured along the first face 705 betweenthe first end 710 and the second end 712 and a length measuredperpendicular to its height.

The fin head 700 is made of rigid silicone, which has a high durometer.In alternate embodiments, the fin head 700 is composed of any rigidbio-compatible material, such as a rigid bio-compatible polymericmaterial.

The flexible joining material 702 comprises a rectangular sheet having afirst face 720, a second face 721, a first end 718 and a second end 719.The flexible joining material 702 further comprises a height measuredalong the first face between the first end 718 and the second end 719.The flexible joining material 702 also comprises a length measuredperpendicular to its height. The length of the flexible joining material702 is the same as the length of fin head 700.

The second end 712 of the second face 706 of the fin head 700 isattached to the first end 718 of the first face 720 of the flexiblejoining material 702. The fin head 700 is attached to the flexiblejoining material 702 with stitching 725. The second end 719 of the firstface 720 of the flexible joining material 702 is attached to the firstsurface 131 of the backing material 130. The flexible joining material702 is attached to the backing material 130 with stitching 730.

The flexible joining material 702 is made of flexible silicone. It willbe recognized by one skilled in the art, however, that the flexiblejoining material 702 may be made from many other flexible materials,such as a flexible polymeric material.

FIG. 30( b) illustrates a property of the fin 120. When pressure isapplied perpendicular to the first surface 705 of the fin head 205, thefin 120 folds as shown. When the fin 120 folds, its appendage height,H_(Appendage), is reduced. This can be seen by a comparison between FIG.30( a), which shows the fin 120 in an upright position and FIG. 30( b)that shows the fin 120 in a folded position.

FIG. 30( c) illustrates a top planar view of the lead electrode assembly100 of the embodiment illustrated in FIGS. 30( a)-30(b). Neither thecorners of the electrode 107 nor the corners 735 of the backing layer130 of this embodiment are rounded. In an alternate embodiment, both thecorners of the electrode 107 and the corners 735 of the backing layer130 of this embodiment are rounded.

FIG. 31 illustrates an alternative embodiment of the lead electrodeassembly 100. This embodiment is substantially similar to the embodimentillustrated in FIGS. 30( a)-30(d). The backing layer 130 of thisembodiment, however, lacks a fin head 700 and flexible joining material702.

Moreover, the appendage 118 in this embodiment comprises a tube 740having an interior 755, an exterior 756, a proximal end 757 and a distalend 758. The tube comprises a sheet of material 750. The sheet ofmaterial 750 is substantially rectangular having a first pair of sides751, a second pair of sides 752, a first surface 753 and a secondsurface 754.

The sheet of material 750 is folded so that its first pair of sides 751abuts each other. The folded sheet of material 750 forms a tube 740. Thefirst surface 753 of the sheet of material 750 faces the interior 755 ofthe tube 740. The second surface 754 of the sheet of material 750 facesthe exterior of the tube 756. In folding the sheet of material 750 sothat the first pair of sides 751 abuts each other, the second pair ofsides 752 of the sheet of material 750 is folded in a circular shape toform the proximal end 757 and distal end 758 of the tube 740. Thisresults in the tube 740 having a cylindrical shape. The diameter of thecircular proximal end 757 and distal end 758 of the tube 756 isapproximately 5 mm. In alternate embodiments, the diameter range betweenapproximately 1 mm and approximately 10 mm. The length of the tube 756as measured between the proximal end 757 and distal end 758 of the tube756 is approximately 1 cm. In alternate embodiments, length of the tube756 ranges between approximately 2 mm and approximately 6 cm. In oneembodiment, the tube 756 is substantially as long as the electrode 107.

The second surface 754 of the sheet of material 750 is attached to thefirst surface 131 of the backing layer 130. The first pair of sides 751of the sheet of material 750 is attached to the backing layer 130 withstitching 760.

In alternate embodiments, the proximal end 757 of the tube 740 isclosed. In one embodiment, the proximal end 757 of the tube 740 isclosed by a cap (not shown). In another embodiment, the proximal end 757of the tube 740 is closed by holding one of the second pair of sides 752of the sheet of material 750 closed with stitching. In anotherembodiment, the proximal end 757 of the tube 740 is closed by any othermeans known in the art for this purpose.

It should be noted that the appendage 118 in some alternativeembodiments comprises a tube with a shape other than a cylinder. Anexample of a tube with a shape other than cylindrical is illustratedbelow in FIG. 32.

FIG. 32 illustrates an alternative embodiment of the lead electrodeassembly 100. This embodiment is substantially similar to the embodimentillustrated in FIG. 31. The tube 740 comprising a sheet of material 750,however, is absent from this embodiment.

Moreover, the appendage 118 of this embodiment comprises a tube 770having an interior 755 an exterior 756, a proximal end 757 and a distalend 758. The tube comprises a first sheet of material 775, a secondsheet of material 776 and a third sheet of material 777. The first sheetof material 775, the second sheet of material 776 and the third sheet ofmaterial 777 are all substantially rectangular in shape. Each comprisesa first pair of sides 784, a second pair of sides 786, a first surface788 and a second surface 789. The first pair of sides 784 of each sheetof material is parallel to each other. In another embodiment, the firstpair of sides 784 of each sheet of material is non-parallel. The secondpair of sides 786 of each sheet of material is parallel to each other.In another embodiment, the second pair of sides 786 of each sheet ofmaterial is non-parallel.

The first pairs of sides 784 of each sheet of material are attached tothe first pair of sides 784 of the other sheets of material. In this waythe second pair of sides 786 of the first sheet of material 775, thesecond sheet of material 776 and the third sheet of material 777 form atriangular shaped proximal end 757 and distal end 758 of the tube 770.The sheets of material are attached to each other such that the secondsurface 789 of each sheet of material faces the interior 755 of the tube770. The sheets of material are attached to each other with stitching791.

The height of the tube 770 is approximately 5 mm. In alternateembodiments, the height ranges between approximately 1 mm andapproximately 10 mm. The length of the tube 770 as measured between theproximal end 757 and distal end 758 of the tube 770 is approximately 1cm. In alternate embodiments, length of the tube 770 ranges betweenapproximately 2 mm and approximately 6 cm. In one embodiment, the tube770 is substantially as long as the electrode 107.

The second sheet of material 776 is attached to the backing layer 130with stitching 790. The first surface 788 of the second sheet ofmaterial 776 is positioned next to the first surface 131 of the backinglayer 130.

In alternate embodiments, some or all of the sheets of material arereinforced with a layer of Dacron® polymer mesh. In one embodiment, theDacron® polymer mesh is attached to the first surface 788 of each sheetof material. In another embodiment, the Dacron® polymer mesh is attachedto the second surface 789 of each sheet of material. In anotherembodiment, the sheets of material are similarly reinforced with a layerof any polymeric material.

In alternate embodiments, the proximal end 757 of the tube 770 isclosed. In one embodiment, the proximal end 757 of the tube 770 isclosed by a cap. In another embodiment, the proximal end 757 of the tube770 is closed by holding the sides 786 of the first sheet of material775, the second sheet of material 776 and the third sheet of material777 that form the proximal end 757 of the tube 770 together withstitching. In another embodiment, the proximal end 757 of the tube 770is closed by any other means known in the art for this purpose.

FIGS. 33( a)-33(d) illustrate various possible positions for theappendage 118 relative to the lead 21 of the lead electrode assembly100. Additionally, up to this point, all embodiments of the electrode107 illustrated and discussed have had a rectangular shape. Thesefigures illustrate alternative embodiments with electrodes 107 ofdifferent shapes.

At this point, it is useful to set out two definitions in order todiscuss the possible orientation of appendages 118.

The interface line is defined as the center line of the appendage 118 astraced on the electrode 107. FIG. 33( a) illustrates the interface line800 of the appendage 118 of a lead electrode assembly 100.

The line of the lead is defined as the line along which the lead 21 ofthe lead electrode assembly 100 enters the lead fastener 146. The lineof the lead 805 of line 21 is shown as it enters the lead fastener 146(in phantom). As the lead 21 approaches the lead fastener 146, theclosest section 807 of the lead 21 forms the line of the lead. When thelead 21 is not bent, the entire lead 21 lies along the line of the lead.

FIG. 33( b) illustrates an embodiment wherein the lead 21 is not bentand the entire lead 21 lies along the line of the lead 805.

The electrode length, L_(Electrode), is the length of the electrode 107as measured along the interface line 800.

In the embodiments of the lead electrode assembly 100 shown in FIGS. 33(b) and 33(c), the interface line 800 is the same line as the line of thelead 805. In the embodiment shown in FIG. 33( a) the interface line 800is parallel with the line of the lead 805.

In the embodiment of the lead electrode assembly 100 shown in FIG. 33(d), the interface line 800 intersects the lead fastener 146 (phantomview).

FIGS. 33( e)-33(h) show various additional electrode shapes disposed invarious lead electrode assemblies 100. The electrode shapes are notlimited, however, to the shapes specifically illustrated.

The electrode 204 depicted in FIG. 33( e) has a “thumbnail” shape. Theproximal end 104 of this electrode 107 is generally rounded. As theelectrode 107 moves distally along its length, the conductive surfaceterminates at the distal end 103 of the electrode 107.

An ellipsoidal shaped electrode 107 is depicted in FIG. 33( f). Theproximal end 104 of the ellipsoidal shaped electrode 107 is generallyrounded. As the ellipsoidal shaped electrode 107 moves distally alongits length, the conductive surface terminates in a rounded distal end103.

A circular shaped electrode 107 is illustrated in FIG. 33( g).

A triangular shaped electrode 107 is depicted in FIG. 33( h). Triangularshaped electrodes 107 also incorporate electrodes that are substantiallytriangular in shape. In particular to FIG. 33( h), the corners of thetriangular shaped electrode 107 are rounded.

Several lead electrode assembly manipulation tools 927 have beendeveloped to manipulate the lead electrode assemblies during theirsurgical implantation.

FIG. 34 illustrates an embodiment of a lead electrode assemblymanipulation tool 927. The lead electrode assembly manipulation tool 927comprises an enhanced hemostat 930 used to manipulate lead electrodeassemblies 100 comprising an eyelet during their implantation inpatients.

The enhanced hemostat 930 comprises the following components: a hemostathaving a first prong 931, a second prong 932, a hinge 939 and an eyeletpin 940. The first prong 931 is attached to the second prong 932 by thehinge 939. The eyelet pin is attached to the second prong 932.

The first prong 931 comprises a first end 933 and a second end 934. Thesecond prong 932 comprises a first end 935 and a second end 936. Thefirst prong and second prong are approximately 75 cm long and curvedwith a radius of approximately 30 cm. In alternate embodiments, thecurvature of the hemostat does not have a radius of approximately 30 cm,but instead approximates the curvature of the thorax of a patient. Inone embodiment, the curvature of the hemostat approximates the curvatureof the thorax of a patient along a subcutaneous path taken from theanterior axillary line, posteriorly toward the spine.

The first prong 931 is pivotally attached to the second prong 932 by thehinge 939. The hinge is attached to the first prong 931 approximately 10cm from the first end 933. In this embodiment, the hinge is attached tothe second prong 932 approximately 10 cm from the second end 935.

The eyelet pin 940 can be inserted through the eyelet 301 of a fin 120of the lead electrode assembly 100 such as the lead electrode assembly100 discussed with reference to FIGS. 22( a)-22(g) as a means ofcapturing the lead electrode assembly 100 prior to its implantation in apatient.

The eyelet pin 940 is a cylindrical member having a first end 941 and asecond end 942. In an alternate embodiment, the eyelet pin 940 is ahook-shaped member. The diameter of the cylinder is approximately 2 mm.In alternate embodiments, the diameter of the cylinder ranges fromapproximately 1 mm to approximately 5 mm. The length of the eyelet pin940 is approximately 8 mm. In alternate embodiments, the length of theeyelet pin 940 ranges from approximately 4 to approximately 15 mm.

The first end of the eyelet pin 940 is attached to the second prong 932,approximately 8 mm from the second end 936 of the second prong 932. Inalternate embodiments, the eyelet pin 940 is attached to the secondprong 932 at various lengths from the second end 936 of the second prong932.

The eyelet pin 940 is attached to the second prong 932 in an orientationperpendicular to the length of the second prong 932. The eyelet pin 940is attached to the second prong 932 so that it extends away from thesecond end 934 of the first prong 931.

In this embodiment, all of the components are made of stainless steel.In an alternative embodiment, some or all of the components are composedmetals other than stainless steel or are composed of a polymericmaterial.

We now turn to a discussion of the positions of the components thatcomprise an entire S-ICD system including the lead electrode assembly100 when it is implanted in a patient.

FIGS. 35( a) and 35(b) illustrate an embodiment of the S-ICD systemimplanted in a patient as a means of providingcardioversion/defibrillation energy.

FIG. 35( a) is a perspective view of a patient's ribcage with animplanted S-ICD system. The 5-ICD canister 11 is implantedsubcutaneously in the anterior thorax outside the ribcage 1031 of thepatient, left of the sternum 920 in the area over the fifth rib 1038 andsixth rib 1036. The S-ICD canister 11, however, may alternately beimplanted anywhere over the area between the third rib and the twelfthrib. The lead 21 of the lead electrode assembly 100 is physicallyconnected to the S-ICD canister 11 where the transthoracic cardiacpacing energy or effective cardioversion/defibrillation shock energy(effective energy) is generated. The term “effective energy” as used inthis specification can encompass various terms such as field strength,current density and voltage gradient.

The lead 21 of the lead electrode assembly 100 travels from the S-ICDcanister 11 to the electrode 107, which is implanted subcutaneously inthe posterior thorax outside the ribcage 1031 of the patient in the areaover the eighth rib 1030 and ninth rib 1034. The electrode 107, mayalternately be implanted subcutaneously anywhere in the posterior thoraxoutside the ribcage 1031 of the patient in the area over the third rib1030 and the twelfth rib 1034. The bottom surface 115 of the electrode107 faces the ribcage. The electrode or active surface 15 (phantom view)of the canister 11 also faces the ribcage.

FIG. 35( b) is a cross-sectional side plan view of the patient's ribcage. Here it is seen that the lead 21 travels around the circumferenceof the thorax, in the subcutaneous layer beneath the fat 1050 betweenthe outside of the ribcage 1031 and the skin 1055 covering the thorax.

We now turn to a discussion of a method by which the lead electrodeassembly 100 of the S-ICD system is implanted in a patient using astandard hemostat as well as the enhanced hemostat described above. FIG.36 and FIGS. 37( a)-37(d) illustrate aspects of this method.

In operation, as seen in FIG. 36, an incision 905 is made in the patient900 in the anterior thorax between the patient's third and fifth rib,left of the sternum 920. The incision can alternately be made in anylocation between the patient's third and twelfth rib. The incision canbe made vertically (as shown), horizontally or angulated. In order tominimize scarring, the incision can be made along Langher's lines.

FIG. 37( a) shows a bottom view cross-section of the patient 900, alongthe line 37(a) shown in FIG. 36. A hemostat 930, with prongs 932 isintroduced into the incision 905. The hemostat 930 is inserted with itsprongs together without anything gripped between them. The prongs 932 ofthe hemostat 930 are pushed through the fat 1050 between the skin 1055of the thorax and the ribcage 1031 to create a subcutaneous path 1090.The prongs 932 of the hemostat 930 can alternately be pushed beneath thefat 1050 that lies between the skin 1055 of the thorax and the ribcage1031 to create a subcutaneous path 1090 between the fat 1050 and theribcage 1031.

The hemostat is moved around the ribcage 1031 until the subcutaneouspath 1090 reaches within approximately 10 cm of the spine 1035 betweenthe eighth rib 1030 and ninth rib 1034 (this location is best seen inFIG. 35( a)) between the skin 1055 and the ribcage 1031. Thesubcutaneous path 1090 can alternately be made to reach any locationbetween the skin 1055 and the ribcage 1031 between the patient's thirdand twelfth rib. The hemostat 930 is then withdrawn. Alternately, thehemostat 930 can be moved around the ribcage 1031 until the subcutaneouspath 1090 terminates at a termination point 1085 at which a line 1084drawn from the termination point 1085 to the incision 905 wouldintersect the heart 910.

Next, as shown in FIG. 37( b), the appendage 118 of a lead electrodeassembly 100 is squeezed between the tongs 932 of a hemostat 930.

As shown in FIG. 37( c), the lead electrode assembly 100 and hemostattongs 932 are introduced to the subcutaneous path 1090 and pushedthrough the subcutaneous path until the lead electrode assembly 100reaches the termination point 1085 of the path. The appendage 118 of thelead electrode assembly 100 is then released from the tongs 932 of thehemostat 930. The hemostat 930 is then withdrawn from the subcutaneouspath 1090.

In an alternative method, the enhanced hemostat 930 seen in FIG. 34 isused to introduce the lead electrode assembly 100 into the subcutaneouspath 1090 created as discussed above. After the subcutaneous path 1090is created, the lead electrode assembly 100 is attached to the enhancedhemostat 930 as shown in FIG. 37( d). Eyelet pin 1108 is insertedthrough the eyelet 301 in the fin 120 of the lead electrode assembly100. The enhanced hemostat 930 is then used to introduce the leadelectrode assembly 100 into the subcutaneous path 1090, as shown in FIG.37( c). The lead electrode assembly 100 is then moved through thesubcutaneous path 1090 until the electrode 107 reaches the end of thepath 1085. The enhanced hemostat 930 is then moved until the leadelectrode assembly 100 is released from the eyelet pin 940. The enhancedhemostat 930 is then withdrawn from the subcutaneous path 1090.

FIGS. 38( a)-38(c) illustrate an alternative embodiment of the leadelectrode assembly 100. This embodiment is substantially similar to theembodiments illustrated in FIGS. 22( a)-22(g). The backing layer 130 ofthis embodiment, however, lacks an integrated fin tab 180. Moreover, theappendage 118 of the lead electrode assembly 100 of this embodimentcomprises a rail 1100.

FIG. 38( a) illustrates the rail 1100 of the lead electrode assembly 100of this embodiment. The rail 1100 is a member attached to the electrode107 that can be captured by a lead electrode assembly manipulation tooland used to precisely locate the electrode 107 during its surgicalimplantation within the patient. The rail 1100 comprises three sections:a foundation 1105, a riser 1110 and a head 1115. The foundation 1105 isseparated from the head 1115 by the riser 1125.

The foundation 1105 comprises a flat, substantially planar member,comprising a first pair of sides 1106 and a second pair of sides 1107.The first pair of sides 1106 of the foundation 1105 is substantiallylinear and substantially parallel. In an alternate embodiment, the firstpair of sides 1106 of the foundation 1105 is neither linear norparallel. The length of the first pair of sides 1106 of the foundation1105 is approximately 2 cm. In alternate embodiments, the length of thefirst pair of sides 1106 of the foundation 1105 ranges fromapproximately 2 mm to approximately 6 cm. In an alternate embodiment,the first pair of sides 1106 of the foundation 1105 is as long as theelectrode 107 (not shown) of the lead electrode assembly 100 (notshown).

The second pair of sides 1107 of the foundation 1105 is substantiallylinear and substantially parallel. In an alternate embodiment, thesecond pair of sides 1107 of the foundation 1105 is neither linear norparallel. The length of the second pair of sides 1107 of the foundation1105 is approximately 1 cm. In alternate embodiments, the length of thesecond pair of sides 1107 of the foundation 1105 ranges fromapproximately 0.5 cm to approximately 3 cm.

The foundation 1105 further comprises a top surface 1120 and a bottomsurface 1121. The foundation 1105 has a thickness, measured as thedistance between the top surface 1120 and the bottom surface 1121. Thethickness of the foundation 1105 is 2 mm. In alternate embodiments, thethickness of the foundation 1105 ranges between approximately 1 mm andapproximately 5 mm.

Turning now to the riser 1110, the riser 1110 comprises a flat,substantially planar protrusion from the top surface 1120 of thefoundation 1105 of the rail 1100. The riser comprises a first face 1125,a second face 1126, a top 1127, a bottom 1128, a proximal end 1123 and adistal end 1124. The first face 1125 and second face 1126 are parallelto each other and perpendicular to the top surface 1120 of thefoundation 1105. The first face 1125 and a second face 1126 of the riser1110 are parallel to the first pair of sides 1106 of the foundation1105. The bottom 1128 of the riser 1110 joins the foundation 1105 in aposition centered between the first pair of sides 1106 of the foundation1105. The proximal end 1123 of the riser 1110 and the distal end 1124 ofthe riser 1110 are parallel to each other and perpendicular to the topsurface 1120 of the foundation 1105. In other embodiments, the proximalend 1123 of the riser 1110 and the distal end 1124 of the riser 1110 arenot parallel to each other.

In one embodiment, the proximal end 1123 of the riser 1110 is notperpendicular the top surface 1120 of the foundation 1105. Instead, theproximal end 1123 of the riser 1110 is sloped, so that the proximal end1123 and the distal end 1124 of the riser 1110 are closer at the top1127 of the riser 1110 than at the bottom 1128 of the riser. A slantedproximal end 1123 make the rail 1100 of the lead electrode assembly 100offer less resistance against the tissues of the patient duringinsertion into the patient.

The height of the riser, H_(Riser) is measured as the distance betweenthe top surface 1120 of the foundation 1105 to the head 1115,perpendicular to the top surface 1120 of the foundation 1105. The heightof the riser is approximately 5 mm. In alternate embodiments, the heightof the riser ranges from approximately 1 mm to approximately 10 mm.

The riser 1110 has a width, measured as the distance between the firstface 1125 and the second face 1126. The width of the riser 1110 is 2 mm.In alternate embodiments, the width of the riser 1110 ranges fromapproximately 1 mm to approximately 6 mm.

Turning now to the head 1115, the head 1115 is a flat, substantiallyplanar member. The head 1115 comprises a first pair of sides 1136, asecond pair of sides 1137, a top surface 1116 and a bottom surface 1117(not shown). The first pair of sides 1136 and the second pair of sides1137 of the head 1115 are substantially linear and substantiallyparallel. In an alternate embodiment, the first pair of sides 1136 ofthe head 1115 is neither linear nor parallel. In an alternateembodiment, the second pair of sides 1137 of the head 1115 is neitherlinear nor parallel.

The length of the first pair of sides 1136 of the head 1115 is equal tothe length of the first pair of sides 1106 of the foundation 1105. Inalternate embodiments, the length of the first pair of sides 1136 of thehead 1115 is unequal to the length of the first pair of sides 1106 ofthe foundation 1105. The length of the second pair of sides 1137 of thehead 1115 is approximately 5 mm. In alternate embodiments, the length ofthe second pair of sides 1137 of the head 1115 ranges from approximately3 mm to approximately 10 mm.

The bottom surface 1117 of the head 1115 joins the top 1127 of the riser1110 opposite the foundation 1105 of the rail 1100. The top surface 1116and the bottom surface 1117 of the head 1115 are parallel to the topsurface 1120 of the foundation 1105. In an alternate embodiment, the topsurface 1116 and the bottom surface 1117 of the head 1115 are notparallel to the top surface 1120 of the foundation 1105.

The head 1115 has a thickness, measured as the distance between the topsurface 1116 and the bottom surface 1117 of the head 1115. The thicknessof the head 1115 is approximately 2 mm. In alternate embodiments, thethickness of the head ranges between approximately 2 mm andapproximately 10 mm.

The foundation 1105, the head 1115 and the riser 1110 are made ofstainless steel. In alternate embodiments, some or all of the sectionsof the rail 1100 are made of metals other than stainless steel. Inalternate embodiments, some or all of the sections of the rail 1100 aremade of a polymeric material wherein the polymeric material is selectedfrom the group consisting essentially of a polyurethane, a polyamide, apolyetheretherketone (PEEK), a polyether block amide (PEBA), apolytetrafluoroethylene (PTFE), a silicone and mixtures thereof.

The foundation 1105, the head 1115 and the riser 1110 are machined fromthe same piece of material. In an alternate embodiment, some or all ofthe sections are formed independently and welded to the others.

Turning in detail to FIG. 38( b), the position of the rail 1100 withinthe lead electrode assembly 100 will be discussed. The rail 1100 ispositioned so that its bottom surface 1121 is adjacent to and covers aregion of the first surface 131 of the backing layer 130. The rail iscentered between the first side 133 and second side 134 of the backinglayer 130. In an alternate embodiment, the rail is not centered betweenthe first side 133 and second side 134 of the backing layer 130.

In an alternate embodiment, there is no backing layer 130 and the rail1100 is positioned so that its bottom surface 1121 is adjacent to thetop surface 110 of the electrode 107.

Turning now to the electrode 107 of this embodiment, the electrode 107is the same shape and size as the electrode 107 discussed with referenceto FIGS. 22( a)-22(g). In alternative embodiments, the length of thefirst pair of sides 108 (not shown) and second pair of sides 109 (notshown) of the electrode 107 ranges independently between approximately 1cm and approximately 5 cm.

Turning now to the molded cover 220, the skirt 222 of the molded cover220 partially covers the bottom surface 115 of the electrode 107 asdiscussed with reference to FIG. 22( d). The molded cover 220 furthersubstantially covers the first surface 131 of the backing layer 130. Themolded cover 220 does not cover the first surface 131 of the backinglayer 220 in the region in which the bottom surface 1121 of the rail1100 is adjacent to the backing layer 130. Instead, the molded cover 220in this region substantially covers the top surface 1120 of the rail1100. The molded cover 220 abuts the first face 1125 and second face1126 of the riser 1110 of the rail 1100.

Turning to FIG. 38( c), the position of the lead 21 and the appendage118 will now be discussed. The interface line 800 of the appendage 118and the line of the lead 805 are the same line. In an alternateembodiment, interface line 800 of the appendage 118 and the line of thelead 805 are not the same line. The line of the lead 805 is centeredbetween the first pair of sides 108 (phantom view) of the electrode 107(phantom view). In an alternate embodiment, the line of the lead 805 isnot centered between the first pair of sides 108 of the electrode 107.

FIG. 39 illustrates an alternative embodiment of the lead electrodeassembly 100. This embodiment is substantially similar to the embodimentillustrated in FIGS. 38( a)-38(c). In this embodiment, however, thedimensions of the electrode 107 are different from those of theembodiment illustrated in FIGS. 38( a)-38(c).

The first pair of sides 108 of the electrode 107 (phantom view) isapproximately 2.4 cm in length. The second pair of sides 109 of theelectrode 107 is approximately 4 cm in length. In alternativeembodiments, the length of the first pair of sides 108 and second pairof sides 109 of the electrode 107 ranges independently betweenapproximately 1 cm and approximately 5 cm.

The interface line 800 of the rail 1100 is parallel to the line of thelead 805. In an alternate embodiment, the interface line 800 of the rail1110 is not parallel to the line of the lead 805. The interface line 800of the rail 1100 is centered between the first pair of sides 108 of theelectrode 107. In an alternate embodiment, the interface line 800 of therail 1100 is not centered between the first pair of sides 108 of theelectrode 107.

The line of the lead 805 is not centered between the first pair of sides108 of the electrode 107. Because the lead 805 is not centered betweenthe first pair of sides 108 of the electrode 107, the lead rail 1110 maybe more easily accessed by a lead electrode manipulation tool (notshown). In an alternate embodiment, the line of the lead 805 is centeredbetween the first pair of sides 108 of the electrode 107.

FIG. 40 illustrates a lead electrode assembly manipulation tool 927useful for manipulating a lead electrode assembly (not shown) having anappendage 118 comprising a rail 1100 during the implantation of the leadelectrode assembly 100 in a patient. Examples of such lead electrodeassembly 100 embodiments are shown in FIGS. 38( a)-38(c) and 39.

The lead electrode assembly manipulation tool 927 comprises a handle1142, a rod 1144 and a rail fork 1146. The handle 1142 is connected tothe rod 1144. The rail fork 1146 is also connected to the rod 1144.

The rod 1144 is a cylindrical member with a diameter of approximately 4mm, approximately 25 cm in length, having a proximal end 1147 and adistal end 1148. The rod 1144 is curved with a radius of approximately20 cm.

The rod is made of steel. In other embodiments, the rod is composed oftitanium, a polymeric material or any other material suitable for thispurpose.

The handle 1142 is a cylindrical member with a diameter sized to fitcomfortably in the palm of a surgeon's hand. The rod is connected to theproximal end 1147 of the rod 1144. In an alternate embodiment, thehandle 1142 is not cylindrical. In an alternate embodiment, the handle1142 has ergodynamic contours.

The handle is made of polyurethane. In an alternate embodiment, thehandle is made of any metal, or any polymeric material suitable for thispurpose.

Turning now to FIG. 40( b), the rail fork 1146 is attached to the distalend 1148 of the rod 1144. The rod further comprises a slot 1162 in itsdistal end. The rail fork comprises a pair of tines 1151 separated by agap 1153 and a tine base 1160 having a tang 1161.

Each of the pair of tines 1151 has a proximal end 1154 and a distal end1155. The proximal ends 1154 of the pair of tines 1151 are attached tothe tine base 1160. Each of the pair of tines 1151 has a substantiallyrectangular form with straight inner sides 1156 and straight outer sides1157. The distal ends 1155 of each of the pair of tines 1151 arerounded. The length of the pair of tines 1151, measured from the distalend 1155 to the proximal end 1154, is substantially equal to the lengthof the first pair of sides 1106 of the rail 1100 of the lead electrodeassembly 100. In alternate embodiments, the length of the pair of tines1151 is substantially greater than or less than the length of the firstpair of sides 1106 of the rail 1100.

The pair of tines 1151 is separated by a gap 1153 formed by the innersides 1156 of the pair of tines 1151 and the tine base 1160.

The pair of tines 1151 and the tine base 1160 comprising the rail fork1146 are punched from a single sheet of steel having a thickness ofapproximately 3 mm. In other embodiments, the rail fork 1146 is composedof titanium, a polymeric material or any other material suitable forthis purpose. In one embodiment, the handle 1142, the rod 1144 and therail fork 1146 are all made from the same piece of material.

FIG. 40( c) illustrates a side plan view of the lead electrode assemblymanipulation tool 927. The rod 1144 further comprises a slot 1162 in itsdistal end 1148. The tine base 1160 connects the pair of tines 1151 tothe distal end 1148 of the rod 1144. The tine base 1160 comprises a tang1161 (phantom view). The tang 1161 is inserted in the slot 1162 in therod 1144. The tang 1161 is welded in the slot 1162 of the rod 1144.

We now turn to a description of the use of the lead electrode assemblymanipulation tool 927 in the implantation of a lead electrode assembly100 into a patient.

As discussed with reference to FIG. 36, an incision 905 is made in thepatient 900. As discussed with reference to FIG. 37( a), a subcutaneouspath 1090 is created in the patient 900 with a hemostat 932.

As shown in FIG. 40( d), the lead electrode assembly 100 is thencaptured by the lead electrode assembly manipulation tool 927. The rail1110 of the lead electrode assembly 100 is inserted into the rail fork1146 of the lead electrode assembly manipulation tool 927. The riser1110 (phantom view) of the rail is placed into the gap 1153 between thepair of tines 1151 of the rail fork 1146. The pair of tines 1151 fitsbetween the bottom surface 1117 of the head 1115 of the rail 1100 andthe molded cover 220. The rail 1100 is slid toward the proximal end 1155of the pair of tines 1151 until the riser 1110 of the rail 1100 reachesthe tine base 1160 of the rail fork 1146. The lead 21 of the leadelectrode assembly 100 can then be pulled in toward the handle 1142 ofthe lead electrode assembly manipulation tool 927 until it is taut. Thisacts to prevent the rail 1100 of the lead electrode assembly 100 fromsliding toward the distal end 1151 of the pair of tines 1151 of the railfork 1146.

As discussed with reference to FIG. 37( c), the lead electrode assemblymanipulation tool 927 may then be used to place the lead electrodeassembly 100 into the incision 905 of the patient 900 and used to movethe electrode 107 to the termination point 1085 of the subcutaneous path1090.

The lead electrode assembly 100 is then released from the lead electrodeassembly manipulation tool 927. To achieve this, the lead 21 of the leadelectrode assembly 100 is released so that the pair of tines 1151 of therail fork 1146 of the lead electrode assembly manipulation tool 927 canslide relative to the rail 1100 of the lead electrode assembly 100. Thelead electrode assembly manipulation tool 927 may then be extracted fromthe subcutaneous path 1090, leaving the lead electrode assembly 100behind.

FIGS. 41( a)-41(b) illustrate an alternative embodiment of the leadelectrode assembly 100. This embodiment is substantially similar to theembodiments illustrated in FIGS. 22( a)-22(g). The backing layer 130 ofthis embodiment, however, lacks an integrated fin tab 180. Moreover, thelead electrode assembly 100 of this embodiment further comprises apocket 1300.

FIG. 41( a) illustrates a cross-sectional side plan view of thisembodiment. The pocket 1300 comprises a layer of material 1315 andstitching 360. The pocket further comprises an interior 1305 and anopening 1310. The layer of material 1315 is attached to the molded cover220 with the stitching 360. The molded cover 220 is, in turn, attachedto the electrode 107.

The molded cover 220 comprises an outer surface 1330 and a top surface1331. The outer surface 1330 of the molded cover 220 is the surface ofthe molded cover 220 that does not lie adjacent to the backing layer 131or the electrode 107. The top surface 1331 of the molded cover 220 facesaway from, and parallel to the electrode 107.

The layer of material 1315 of the pocket 1300 comprises an inner face1316 and an outer face 1317. The layer of material 1315 is attached tothe top surface 1331 of the molded cover 220 so that the inner face 1316of the layer of material 1315 faces the top surface 1331 of the moldedcover 220. The inner face 1316 of the layer of material 1315 also facesthe top surface 110 of the electrode 107.

The layer of material 1315 is made of polyurethane. In otherembodiments, the layer of material 1315 is made of any bio-compatiblematerial suitable for this purpose. In other embodiments, the layer ofmaterial 1315 is made of any bio-compatible polymeric material.

The stitching 360 fastening the layer of material 1315 to the topsurface 1331 of the molded cover 220 is comprised of nylon. In alternateembodiments, the stitching 360 comprises any polymeric material.

FIG. 41( b) illustrates a top plan view of the lead electrode assembly100 of FIG. 41( a). The top surface 1331 of the molded cover 220 has afirst side 1333, a second side 1334, a distal end 1336, a proximal end1337, a length and a width.

The distal end 1336, proximal end 1337, first side 1333 and second side1334 of the top surface 1331 of the molded cover 220 are positionedsubstantially over the distal end 137 (phantom view), proximal end 138(phantom view), first side 133 (not shown) and second side 134 (notshown) of the backing layer 130 (phantom view) respectively.

The width of the top surface 1331 of the molded cover 220 is measured asthe distance between the first side 1333 and second side 1334 of theback surface. The length of the top surface 1331 of the molded cover ismeasured as the distance between the distal end 1336 and proximal end1337 of the molded cover 220.

The layer of material 1315 comprises a periphery 1318 and a middleportion 1319. More particularly, the layer of material 1315 comprises adistal end 1320, a proximal end 1321, a first side 1322 and a secondside 1323. The periphery 1318 of the layer of material 1315 comprisesthe distal end 1320, the proximal end 1321, the first side 1322 and thesecond side 1323 of the layer of material 1315. The middle portion 1319of the layer of material 1315 comprises the area between the distal end1320, the proximal end 1321, the first side 1322 and the second side1323 of the layer of material 1315.

The pocket 1300 formed by the layer of material 1315 further comprises abounded region 1325 and a center 1326. The bounded region 1325 of thepocket 1300 is attached to the back face 1317 of the molded cover 220.The center 1326 of the pocket 1300 is not attached to the back face 1317of the molded cover 220. Stitching 360 in the bounded region 1325 isused to attach the layer of material 1315 to the molded cover 220.

In the embodiment under discussion, the bounded region 1325 of thepocket 1300 comprises a portion of the periphery 1318 of the layer ofmaterial 1315. The bounded region 1325 of the pocket 1300 comprises theproximal end 1321, the first side 1322 and the second side 1323 of thelayer of material 1315. In this embodiment, the bounded region 1325 ofthe pocket 1300 does not comprise the distal end 1320 of the layer ofmaterial 1315. The center 1326 of the pocket 1300 comprises the middleportion 1319 of the layer of material 1315. The bounded region 1325 iscurved around the center 1326 of the pocket 1300 in a “U” shape. Thebounded region 1325 of the pocket 1300 does not completely enclose thecenter 1326 of the pocket 1300.

In this embodiment, the bounded region 1325 of the pocket comprises acontiguous portion of the periphery 1318 of the layer of material 1315.In an alternate embodiment, the bounded region 1325 of the pocketcomprises a plurality of segmented portions of the periphery 1318 of thelayer of material 1315.

In an alternate embodiment the bounded region 1325 of the pocket 1300does not comprise any portion of the periphery 1318 of the layer ofmaterial 1315. In alternate embodiments, the bounded region 1325comprises any shape that could be traced on the layer of material 1315that partially encloses a center 1326. In one embodiment, the boundedregion 1325 of the pocket 1300 is a portion of a circle's circumference(not shown) that does not touch the periphery 1318 of the layer ofmaterial 1315. The center 1326 is the area inside the circle.

In an alternate embodiment, the pocket 1300 comprises a sheet of moldedsilicone. The molded silicone is fused to the molded cover 220 in thebounded region 1325.

The opening 1310 of the pocket 1300 comprises the area between thedistal end 1320 of the layer of material 1315 and the top surface 1331of the molded cover 220. The interior 1305 of the pocket 1300 comprisesthe area between the middle portion 1319 of the layer of material 1315and the top surface 1331 of the molded cover 220.

The layer of material 1315 is positioned so that its first side 1322 andsecond side 1323 are positioned over the first side 1333 and second side1334 of the top surface 1331 of the molded cover 220 respectively. Thelayer of material 1315 is positioned so that its proximal end 1321 ispositioned over the proximal end 1337 of the top surface 1331 of themolded cover 220.

The layer of material 1315 is sized so that its length is shorter thanthe length of the top surface 1331 of the molded cover 220. In alternateembodiments, the layer of material 1315 is sized so that its length isequal to, or longer than the length of the top surface 1331 of themolded cover 220.

The proximal end 1321 of the layer of material 1315 is sized so that itswidth is substantially equal to the width of the proximal end 1337 ofthe top surface 1331 of the molded cover 220. The layer of material 1315is sized so that its width steadily increases toward its distal end1320.

The first side 1318 of the distal end 1320 of the layer of material 1315is fastened to the first side 1333 of the top surface 1331 of the moldedcover 220. The second side 1323 of the distal end 1320 of the layer ofmaterial 1315 is fastened to the second side 1334 of the top surface1331 of the molded cover 220.

Since the first end 1322 of the layer of material 1315 is wider than thetop surface 1331 of the molded cover 220, the layer of material 1315separates from the top surface 1331 of the molded cover 220 to form theinterior 1305 of the pocket 1300.

In an alternate embodiment, the lead electrode assembly 100 lacks amolded cover 220 and the pocket 1300 is attached directly to the backinglayer 130. In another alternate embodiment the lead electrode assembly100 lacks a molded cover 220 and a backing layer 130 and the pocket 1300is attached directly to the electrode 107. In a further alternateembodiment, the pocket 1300 is molded as part of the molded cover 220.

FIG. 41( c) illustrates a cross-sectional side plan view of analternative embodiment of the lead electrode assembly 100. Thisembodiment is substantially similar to the embodiment illustrated inFIGS. 41( a)-41(b). The backing layer 130 of this embodiment, however,further comprises a fin 120 positioned in the interior 1305 of thepocket 1300. The fin 120 of this embodiment is substantially similar tothe fin 120 of the embodiment illustrated in FIG. 22( b).

The fin 120 comprises an integrated fin tab 180 formed on the backinglayer 130. The molded cover 220 covers the integrated fin tab 180 toform the fin 120. The integrated fin tab 180 has a slope-shaped proximaledge 183. The sloped shape of the resulting fin 120 permits the fin 120to fit deeply into the interior 1305 of the pocket 1300. The hood canact to reduce the resistance presented by the tissues of the patientagainst the fin 120 and any tool used to grasp the fin 120 duringinsertion of the lead electrode assembly 100. Such a hood can be placedover any fin discussed in the specification to perform this function orany other function.

In alternate embodiments, appendages other than a fin are positionedbetween the pocket 1300 and the electrode 107, in the interior 1305 ofthe pocket 1300. In one embodiment, a loop such as that discussed withreference to FIGS. 26( a)-26(c) is positioned in the interior 1305 ofthe pocket 1300. In another embodiment, a tube such as that discussedwith reference to FIG. 31 is positioned in the interior 1305 of thepocket 1300.

FIGS. 42( a) and 42(b) illustrates an alternate embodiment of the leadelectrode assembly 100. This embodiment is substantially similar to theembodiment illustrated in FIGS. 41( a)-41(b).

FIG. 42( a) illustrates a bottom plan view of the lead electrodeassembly 100 of this embodiment. In this embodiment, the electrode 107is thumbnail shaped.

FIG. 42( b) illustrates a top plan view of the lead electrode assembly100 of this embodiment. The top surface 1331 of the molded cover 220 isshaped to accommodate the thumbnail shaped electrode 107.

Like the embodiment discussed with reference to FIGS. 41( a)-41(b), thepocket 1300 comprises a layer of material 1315. In this embodiment,however, the layer of material 1315 has a roughly triangular shape. Thelayer of material 1315 comprises a periphery 1318 and a middle portion1319. More particularly, the layer of material comprises a first side1340, a second side 1341 and a third side 1342 of the layer of material1315. The periphery 1318 of the layer of material comprises the firstside 1340, the second side 1341 and the third side 1342 of the layer ofmaterial 1315. The middle portion 1319 of the layer of material 1315comprises the area between the first side 1340, the second side 1341 andthe third side 1342 of the layer of material 1315.

In this embodiment, the bounded region 1325 of the pocket 1300 comprisesa portion of the periphery 1318 of the layer of material 1315. Thebounded region 1325 of the pocket 1300 comprises the first side 1340 andthe second side 1341 of the layer of material 1315. The center 1326 ofthe pocket 1300 comprises the middle portion 1319 of the layer ofmaterial 1315. The opening 1310 of the pocket 1300 comprises the thirdside 1342 of the layer of material 1315 and the top surface 1331 of themolded cover 220. The bounded region 1325 of the pocket 1300 is curvedaround the center 1326 of the pocket 1300. The bounded region 1325 ofthe pocket 1300 does not completely enclose the center 1326.

In this embodiment, the bounded region 1325 of the pocket comprises acontiguous portion of the periphery 1318 of the layer of material 1315.In an alternate embodiment, the bounded region 1325 of the pocketcomprises a plurality of segmented portions of the periphery 1318 of thelayer of material 1315.

In an alternate embodiment the bounded region 1325 of the pocket 1300does not comprise any portion of the periphery 1318 of the layer ofmaterial 1315.

FIG. 43( a)-43(c) illustrates a lead electrode assembly manipulationtool 927. The lead electrode assembly manipulation tool 927 illustratedis useful for manipulating a lead electrode assembly 100 having a pocket1300 during the implantation of the lead electrode assembly 100 in apatient. Examples of such a lead electrode assembly 100 embodiments areshown in FIGS. 41( a), 41(b), 42(a) and 42(b).

FIG. 43( a) is a top view of the lead electrode assembly manipulationtool 927 of this embodiment. The lead electrode assembly manipulationtool 927 comprises a handle 1142 (not shown), a rod 1144 and a paddle1350.

The rod 1144 and handle 1142 are substantially similar to the rod 1144and handle 1142 of the lead electrode assembly manipulation tool 927illustrated in FIGS. 40( a)-40(d). The handle 1142 is connected to therod 1144.

The paddle 1350 is attached to the distal end 1148 of the rod 1144. Thepaddle 1350 comprises a disk 1351 and a tang 1161 (phantom view).

FIG. 43( b) is a side view of the lead electrode assembly manipulationtool 927 of this embodiment. The tang 1161 is inserted in the slot 1162in the rod 1144. The tang 1161 is welded into the slot 1162 of the rod1144.

The disk 1351 and the tang 1161 are punched from a single sheet of steelhaving a thickness of approximately 3 mm. In other embodiments, the disk1351 and tang 1161 are composed of titanium, a polymeric material or anyother material suitable for this purpose. In one embodiment, the handle1142, the rod 1144 and the paddle 1350 are all made from the same pieceof material.

We now turn to FIG. 43( c) for a description of the use of the leadelectrode assembly manipulation tool 927 in the implantation of a leadelectrode assembly 100 into a patient.

As discussed with reference to FIG. 36, an incision 905 is made in thepatient 900. As discussed with reference to FIG. 37( a), a subcutaneouspath 1090 is created in the patient 900 with a hemostat 932.

The lead electrode assembly 100 is then captured by the lead electrodeassembly manipulation tool 927. The paddle 1350 of the lead electrodeassembly manipulation tool 927 is inserted into the pocket 1300 of thelead electrode assembly 100. The paddle 1350 is slid into the interior1305 of the pocket via the opening 1310 of the pocket until it can go nofurther. At this point, the paddle 1350 touches the inner surface 1316of the proximal end 1321 of the layer of material 1315.

The lead 21 of the lead electrode assembly 100 can then be pulled towardthe handle 1142 of the lead electrode assembly manipulation tool 927until it is taut. This acts to prevent the paddle 1350 of the leadelectrode assembly manipulation tool 927 from sliding out of the pocket1300 of the lead electrode assembly 100.

The lead electrode assembly manipulation tool 927 may then be used toplace the lead electrode assembly 100 into the incision 905 of thepatient as seen in FIG. 36. The lead electrode assembly manipulationtool 927 may then be used to move the electrode 107 to the terminationpoint 1085 of the subcutaneous path 1090 created as discussed withreference to FIG. 37( c).

The lead electrode assembly 100 is then released from the lead electrodeassembly manipulation tool 927. To achieve this, the lead 21 of the leadelectrode assembly 100 is released so that the paddle 1350 can sliderelative to the pocket 1300 of the lead electrode assembly 100. The leadelectrode assembly manipulation tool 927 may then be extracted from thesubcutaneous path 1090 leaving the lead electrode assembly 100 behind.

Alternately, a curved hemostat, such as the hemostat 930 discussed withreference to FIG. 37( b) could be inserted in the pocket 1300 of thelead electrode assembly 100. The hemostat could then be used to move theelectrode 107 to the termination point 1085 of the subcutaneous path1090 as discussed above.

Alternately, a curved hemostat, such as the hemostat 930 discussed withreference to FIG. 37( b) could be used to grip the pocket 1300 of thelead electrode assembly 100, and used to move the electrode 107 to thetermination point 1085 of the subcutaneous path 1090 as discussed above.

FIGS. 44( a)-44(b) illustrate an alternative embodiment of the leadelectrode assembly 100. This embodiment is substantially similar to theembodiment illustrated in FIGS. 43( a)-43(c). The backing layer 130 ofthis embodiment, however, lacks a pocket 1300. Moreover, the leadelectrode assembly 100 of this embodiment further comprises a firstchannel guide 1401 and a second channel guide 1402.

FIG. 44( a) illustrates a cross-sectional rear plan view of the leadelectrode assembly 100 of this embodiment. The first channel guide 1401and a second channel guide 1402 each have an interior 1403 and anopening 1404.

The first channel guide 1401 and the second channel guide 1402 eachcomprise a strip of material 1406 attached to the molded cover 220.

The strip of material 1406 comprising the first channel guide 1401 issubstantially rectangular in shape. The strip of material 1406 comprisesa first side 1410 and a second side 1412. The first side 1410 and thesecond side 1412 of the strip of material 1406 are parallel to eachother. In another embodiment, the first side 1410 of the strip ofmaterial 1406 is not parallel to the second side 1412.

The strip of material 1406 further comprises an inner surface 1417 andan outer surface 1416. The strip of material is positioned so that theinner surface 1417 of the first side 1410 faces the outer surface 1330of the molded cover 220. The first side 1410 of the strip of material isattached to the first side 1333 of the top surface 1331 of the moldedcover 220. The second side 1412 of the strip of material 1406 isattached to the skirt 222 of the molded cover 220.

The interior 1403 of the first channel guide is formed between the innerface 1417 of the strip of material 1406 and the outer surface 1330 ofthe molded cover 220.

The second channel guide is formed in substantially the same way on thesecond side 1334 of the molded cover 220.

FIG. 44( b) illustrates a top plan view of the lead electrode assemblyof the embodiment of FIG. 44( a). The strip of material 1406 comprisingthe first channel guide 1401 is substantially rectangular in shapehaving a distal end 1413 and a proximal end 1414. The distal end 1413and the proximal end 1414 of the strip of material 1406 are parallel toeach other. In another embodiment, the distal end 1413 of the strip ofmaterial 1406 is not parallel to the proximal end 1414 of the strip ofmaterial 1406.

The opening 1404 of the first channel guide 1401 is formed by the distalend 1413 of the strip of material 1406 and the outer surface 1330 of themolded cover 220.

The first side 1410 and the second side 1412 (not shown) of the strip ofmaterial 1406 comprising the first channel guide 1401 are positioned sothat they lie parallel to the first side 1333 (phantom view) of themolded cover 220.

The second channel guide 1402 is formed and mounted to the leadelectrode assembly 100 in substantially the same way as the firstchannel guide 1401. The first side 1410 and the second side 1412 (notshown) of the strip of material 1406 comprising the second channel guide1402 are positioned so that they lie parallel to the second side 1333(phantom view) of the molded cover 220.

The strips of material 1406 are composed of polyurethane. In analternate embodiment, the strips of material 1406 are composed of anypolymeric material. The strips of material 1406 are fastened to themolded cover 220 with stitching 360.

In an alternate embodiment, the strips of material 1406 are made ofmolded silicone and attached to the molded cover 220 by fusing them tothe molded cover 220. In an alternate embodiment, the first channelguide 1401 and the second channel guide 1402 are formed as part of themolded cover 220.

FIGS. 45( a)-45(b) illustrate a lead electrode assembly manipulationtool 927. The lead electrode assembly manipulation tool 927 illustratedis useful for manipulating a lead electrode assembly 100 having a firstchannel guide 1401 and a second channel guide 1402 during theimplantation of the lead electrode assembly 100 in a patient. Examplesof such a lead electrode assembly 100 embodiments are shown in FIGS. 44(a)-44(b).

FIG. 45( a) illustrates a top plan view of a lead electrode assemblymanipulation tool 927. The lead electrode assembly manipulation tool 927in this embodiment comprises a handle 1142 (not shown), a rod 1144 and achannel guide fork 1446.

The rod 1144 and handle 1142 are substantially similar to the rod 1144and handle 1142 of the lead electrode assembly manipulation tool 927illustrated in FIGS. 40( a)-40(d). The handle 1142 is connected to therod 1144.

The channel guide fork 1446 is attached to the distal end 1148 of therod 1144. The channel guide fork 1446 comprises a pair of tines 1451separated by a gap 1455 and a tine base 1450 having a tang 1161.

The pair of tines 1451 each has a proximal end 1452 and a distal end1453. The proximal ends 1452 of the pair of tines 1451 are attached tothe tine base 1450. The pair of tines 1451 has a substantiallycylindrical form. The distal end 1453 of each of the pair of tines 1451is rounded.

The length of the pair of tines 1451 is substantially equal to thelength of the first side 1410 of the strips of material 1406 comprisingthe first channel guide 1401 and second channel guide 1402. In alternateembodiments, the length of the tines 1451 is substantially greater thanor less than the length of the first side 1410 of the strips of material1406 comprising the first channel guide 1401 and second channel guide1402.

The tines are separated by a gap 1455 between the proximal ends 1452 ofthe pair of tines 1451. The pair of tines 1451 is substantially straightand substantially parallel to each other.

The tine base 1450 connects the pair of tines 1451 to the distal end1148 of the rod 1144. The tine base 1450 comprises a tang 1161 (phantomview). The tang 1161 is inserted in a slot 1162 in the rod 1144. Thetang 1161 is welded in the slot 1162 of the rod 1144.

The pair of tines 1451 comprising the channel guide fork 1446 iscomposed of steel and has a diameter of approximately 3 mm. The tinebase 1450 comprising the channel guide fork 1446 is punched from asingle strip of steel having a thickness of approximately 3 mm. The pairof tines 1451 is welded to the tine base 1450.

In other embodiments, the channel guide fork 1446 is composed of metal,a polymeric material, or any other material suitable for this purpose.In one embodiment, the handle 1142, the rod 1144 and the channel guidefork 1446 are all made from the same piece of material.

We now turn to FIG. 45( b) for a description of the use of the leadelectrode assembly manipulation tool 927 in the implantation of a leadelectrode assembly 100 into a patient.

As discussed with reference to FIG. 36, an incision 905 is made in thepatient 900. As discussed with reference to FIG. 37( a), a subcutaneouspath 1090 is created in the patient 900 with a hemostat 932.

The lead electrode assembly 100 is then captured by the lead electrodeassembly manipulation tool 927. The pair of tines 1451 of the leadelectrode assembly manipulation tool 927 is inserted into the openings1404 in the first channel guide 1401 and second channel guide 1402.

The electrode 107 is placed into the gap 1455 between the tines of thechannel guide fork 1446. The tines 1451 fit into the interior 1403 ofthe first channel guide 1401 and second channel guide 1402. The moldedcover is slid toward the proximal end 1452 of the tines until it can gono further. The lead 21 of the lead electrode assembly 100 can then bepulled in toward the handle 1142 of the lead electrode assemblymanipulation tool 927 until it is taut. This acts to prevent the leadelectrode assembly 100 from sliding toward the distal end 1453 of thepair of tines 1451 of the channel guide fork 1446.

The lead electrode assembly manipulation tool 927 may then be used toplace the lead electrode assembly 100 into the incision 905 of thepatient as seen in FIG. 36. The lead electrode assembly manipulationtool 927 may then be used to move the electrode 107 through thetermination point 1085 of the subcutaneous path 1090 created asdiscussed with reference to FIG. 37( c).

The lead electrode assembly 100 is then released from the lead electrodeassembly manipulation tool 927. To achieve this, the lead 21 of the leadelectrode assembly 100 is released so that the pair of tines 1451 of thechannel guide fork 1446 of the lead electrode assembly manipulation tool927 can slide relative to the first channel guide 1401 and secondchannel guide 1402 of the lead electrode assembly 100. The leadelectrode assembly manipulation tool 927 may then be extracted from thesubcutaneous path 1090 leaving the lead electrode assembly 100 behind.

FIG. 46( a) illustrates a subcutaneous implantablecardioverter-defibrillator kit 1201 of the present invention. The kitcomprises a group of items that may be used in implanting an S-ICDsystem in a patient. The kit 1201 comprises a group of one or more ofthe following items: an S-ICD canister 11, a lead electrode assembly100, a hemostat 1205, a lead electrode assembly manipulation tool 927, amedical adhesive 1210, an anesthetic 1215, a tube of mineral oil 1220and a tray 1200 for storing these items.

In one embodiment, the S-ICD canister 11 is the S-ICD canister 11 seenin and discussed with reference to FIG. 1.

The lead electrode assembly 100 is the lead electrode assembly 100 witha rail 1100, and discussed with reference to FIGS. 38( b) and 38(c). Inalternate embodiments, the lead electrode assembly 100 is any leadelectrode assembly 100 including an electrode 107 with an appendage 118;a pocket; or a first and second channel guide for positioning theelectrode 107 during implantation.

The hemostat 1205 is a curved hemostat made of steel having a first end1240 and a second end 1241. The hemostat 1205 has a length, measuredbetween the first end 1240 and the second end 1241 as shown in FIG. 46(b) by dimension L_(Hemostat). The length of the hemostat 1205,L_(Hemostat), is approximately 75 cm. In an alternate embodiment, thehemostat 1205 is a length other than 75 cm. In an alternate embodiment,the hemostat 1205 is the enhanced hemostat seen in and discussed withreference to FIG. 36.

The lead electrode assembly manipulation tool 927 is the lead electrodeassembly manipulation tool 927 with a rail fork 1146. In alternateembodiments, the lead electrode assembly manipulation tool 927 is anylead electrode assembly manipulation tool 927 including a paddle or achannel guide fork.

The medical adhesive 1210 comprises a roll of clear, 1-inch wide medicaladhesive tape. As will be recognized, the medical adhesive could be aliquid adhesive, or any other adhesive substance.

The anesthetic 1215 is a one ounce tube of lidocaine gel. This can beused as a local anesthetic for the introduction of the lead electrodeassembly 100 as discussed below. As will be recognized, the anestheticcould be any substance that has a pain-killing effect. Alternatively,one could use an injectable form of anesthetic inserted along the pathof the lead.

The tube of mineral oil 1220 is a one-ounce tube of mineral oil. Thiscan be used for oiling parts of the electrode connector block 17 seen inFIG. 1.

The tray 1200 is a box sized to fit the items of the kit 1201. The tray1200 is composed of molded plastic. In another embodiment, the tray 1200is a cardboard box. One skilled in the art will recognize that the tray1200 may comprise any container capable of containing the items of thekit. In one embodiment, the tray is formed with recessed partitions 1230that generally follow the outline of the items of the kit 1201 to bestored in the tray. In one embodiment, the tray 1200 has packagingmaterial 1225 disposed over it, wherein the packing material 1225provides a sanitary cover for the items of the kit 1201. The packagingmaterial 1225 further acts to contain the items of the kit 1201.

In an alternate embodiment the kit 1201 comprises ten lead electrodeassemblies 100 each comprising a lead 21 having a lead length, I_(Lead),different from the others. In one embodiment, the lead lengths rangebetween approximately 5 cm and approximately 52 cm with approximately a10 cm difference between the lead length of each lead electrode assembly100.

In an alternative embodiment, the kit 1201 comprises an S-ICD canister11, a hemostat 1205 and an assortment of lead electrode assemblies 100each comprising a lead 21 having a lead length, I_(Lead), different fromthe others.

In one embodiment, the kit 1200 further comprises a tray 1201 and anassortment of lead electrode assemblies 100, each with an electrode 107curved at a radius r different from the others.

In another embodiment, the kit 1200 includes components sized forsurgery on a patient of a particular size. A kit 1200 for a 10 year oldchild, for example, includes an S-ICD canister 11 with a length ofapproximately 10 cm, a lead electrode assembly 100 with a lead length,L_(Lead) of approximately 12 cm and a radius r of approximately 10 cmand hemostat 1205 with a hemostat length, L_(Hemostat), of approximately12 cm.

The S-ICD device and method of the present invention may be embodied inother specific forms without departing from the teachings or essentialcharacteristics of the invention. The described embodiments aretherefore to be considered in all respects as illustrative and notrestrictive, the scope of the invention being indicated by the appendedclaims rather than by the foregoing description and all changes whichcome within the meaning and range of equivalency of the claims aretherefore to be embraced therein.

1. A lead electrode assembly for use in an implantable defibrillatorsystem, the lead electrode assembly comprising: an elongated lead havinga first end for coupling with an implantable defibrillator and a secondend for carrying an electrode, with one or more electrical conductorsextending therein; and an electrode assembly comprising an electrodehaving first and second faces, a backing layer adjacent to the secondface of the electrode and a cover extending over the backing layer andcovering a portion of the first face of the electrode; wherein theelectrode assembly is at the second end of the elongated lead; andwherein the backing layer is precurved to create a radius of curvatureof the electrode matching a desired portion of patient anatomy.
 2. Thelead electrode assembly of claim 1 wherein the desired portion ofpatient anatomy is a selected region of the exterior of a patient'sribs.
 3. The lead electrode assembly of claim 1 wherein the cover is amolded body.
 4. The lead electrode assembly of claim 1 wherein theelectrode assembly includes an appendage extending opposite of the firstface of the electrode in the shape of a fin.
 5. The lead electrodeassembly of claim 4 wherein the appendage includes a pinhole forreceiving a pin of an insertion tool configured to emplace the leadelectrode assembly subcutaneously over the ribcage of a patient.
 6. Thelead electrode assembly of claim 4 wherein the appendage is formed ofportions of the cover and backing layer.
 7. The lead electrode assemblyof claim 4 wherein the backing layer includes a fin extending oppositeof the electrode, and the cover extends over the fin of the backinglayer.
 8. The lead electrode assembly of claim 7 wherein the backinglayer fin and a portion of the cover that extends over the backing layerfin define a pinhole therethrough.
 9. The lead electrode assembly ofclaim 1 wherein the electrode assembly further comprises stitchingsecuring the cover, backing layer and electrode together.
 10. The leadelectrode assembly of claim 1 further comprising engagement meansextending from the cover opposite the first face of the electrode, theengagement means configured to allow engagement with an insertion toolto facilitate placement of the lead electrode assembly subcutaneouslyover the ribcage of a patient.
 11. An implantable defibrillatorcomprising a canister housing operational circuitry for the implantabledefibrillator and a lead electrode assembly coupled to the canister,wherein the lead electrode assembly comprises: an elongated lead havinga first end at the canister and a second end for carrying an electrode,with one or more electrical conductors extending therein; and anelectrode assembly comprising an electrode having first and secondfaces, a backing layer adjacent to the second face of the electrode anda cover extending over the backing layer and covering a portion of thefirst face of the electrode; wherein the electrode assembly is at thesecond end of the elongated lead; and wherein the backing layer isprecurved to create a radius of curvature of the electrode matching adesired portion of patient anatomy.
 12. The implantable defibrillator ofclaim 11 wherein the desired portion of patient anatomy is a selectedregion of the exterior of a patient's ribs.
 13. The implantabledefibrillator of claim 11 wherein the cover is a molded body.
 14. Theimplantable defibrillator of claim 11 wherein the electrode assemblyincludes an appendage extending opposite of the first face of theelectrode in the shape of a fin.
 15. The implantable defibrillator ofclaim 14 wherein the appendage includes a pinhole for receiving a pin ofan insertion tool configured to emplace the lead electrode assemblysubcutaneously over the ribcage of a patient.
 16. The implantabledefibrillator of claim 14 wherein the appendage is formed of portions ofthe cover and backing layer.
 17. The lead electrode assembly of claim 4wherein the backing layer includes a fin extending opposite of theelectrode, and the cover extends over the fin of the backing layer. 18.The implantable defibrillator of claim 17 wherein the backing layer finand a portion of the cover that extends over the backing layer findefine a pinhole therethrough.
 19. The implantable defibrillator ofclaim 11 wherein the electrode assembly further comprises stitchingsecuring the cover, backing layer and electrode together.
 20. Theimplantable defibrillator of claim 11 wherein the lead electrodeassembly further comprises engagement means extending from the coveropposite the first face of the electrode, the engagement meansconfigured to allow engagement with an insertion tool to facilitateplacement of the lead electrode assembly subcutaneously over the ribcageof a patient.